Podcasts about sdss

https://jo.my/8fu6y7 Hazard Communication & Chemical Safety: Safety Data Sheets (SDS) A strong safety culture depends on clear communication, especially when it involves hazardous chemicals. That's where Safety Data Sheets (SDS) come in. These standardized documents are essential for informing, protecting, and preparing everyone in the facility. Understanding SDS is critical to chemical safety, whether you're handling a chemical daily or passing through a storage area. SDSs provide detailed information about the properties, hazards, safe handling, and emergency procedures related to chemical products used in your facility. Every worker has a right to know what chemicals are present, how they might be affected, and what steps to take in case of exposure. Knowing where to find SDSs and how to read them isn't just helpful—it's necessary. Here are a few tips to assist you with understanding and using Safety Data Sheets effectively: Know what an SDS is and why it matters: An SDS document provides key safety information about a chemical. It outlines how to store, handle, and dispose of the material safely and what to do in an emergency. These documents are standardized, making them easy to follow once you understand the format. Understand the structure of an SDS: Most SDSs are split into sections. These sections include identification, hazard identification, composition, first-aid measures, firefighting measures, handling and storage, exposure controls, and more. The first few sections are the most frequently used during daily tasks and emergencies. Always know where SDSs are located: They must always be easy to access, whether in a binder in the break room or through a digital system. Never guess when dealing with chemicals. If you can't find the SDS, stop and ask before proceeding. Use the SDS to prepare and respond: Whether using personal protective equipment, responding to a spill, or treating a chemical exposure, the SDS tells you what steps to take. It's the first line of defense in handling chemical-related incidents correctly. Remember your right to know: Every team member has the right to understand the hazards they may be exposed to. If you don't understand something in an SDS, ask questions. Staying informed helps keep everyone safe. Understanding how to read and use an SDS is not just for emergencies—it's part of working smart and staying safe daily. Make it a habit to review SDSs for any new chemical introduced into your area. To keep this knowledge fresh, reinforce it during toolbox talks and safety meetings. Your safety depends on preparation. With the correct information, you can minimize risks and create a safer work environment for everyone in the facility. Thank you for being part of another episode of Warehouse Safety Tips. Until we meet next time - have a great week, and STAY SAFE! #Safety #SafetyFIRST #SafetyALWAYS #StaySafe #SafetyCulture #ChemicalSafety #SafetyDataSheets #SDSAwareness

https://jo.my/erw5ze Hazard Communication & Chemical Safety: Introduction to Hazard Communication (HazCom) Our topic this month focuses on Hazard Communication, also known as HazCom. This standard is built on a simple principle: every team member has the right to know about the hazardous substances they may come into contact with during their shift. That includes how to handle them safely and what to do if something goes wrong. Hazardous chemicals, ranging from cleaning supplies to fuels, industrial solvents, paints, and everything in between, are present in nearly every facility. These substances can pose serious risks if not identified, stored, and communicated properly. A strong Safety Culture depends on everyone understanding these hazards and following safe practices. Here are a few tips to assist you with staying safe around hazardous chemicals: Know what's in your facility. All chemicals on site should be listed in a Safety Data Sheet (SDS), which must always be available to all team members. If you are unsure about a substance, check the SDS or ask a supervisor for guidance. Read the labels—every time. Before using any chemical, look at the label for hazard warnings, handling instructions, and required personal protective equipment (PPE). Never assume two similar-looking containers hold the same contents. Please follow the signage and posted instructions. Areas with chemical storage or usage will have signs indicating risks—flammable, corrosive, toxic, etc. Respect those warnings. They're there to prevent accidents before they happen. Wear the correct PPE for the job. Depending on the chemical involved, gloves, goggles, respirators, or protective clothing (To name a few) might be required. Using the correct PPE is a key part of protecting yourself from chemical exposure. Be sure to report damaged or missing labels. A label is your first line of defense. If labels are unreadable or missing, please treat the container as unknown and report it immediately. Don't try to guess what's inside. Hazard Communication is more than paperwork, posters, and labels—it's about making sure everyone in the facility understands the risks around them and knows how to act safely. It requires clear communication, consistent training, and a shared responsibility between leadership and staff. Building a safer workplace starts with knowledge. When everyone knows what substances are in use and how to interact with them safely, injuries and exposure incidents decrease. Make it a habit to check labels, read SDSs, and ask questions if something seems wrong. Thank you for being part of another episode of Warehouse Safety Tips. Until we meet next time - have a great week, and STAY SAFE! #Safety #SafetyFIRST #SafetyALWAYS #StaySafe #SafetyCulture #HazardCommunication #ChemicalSafety#PPE #HazCom #SDS #LabelItRight

Waar het precies uit bestaat weten we nog steeds niet, maar astronomen vinden wel steeds meer plaatsen in het heelal waar donkere materie huist. Zo ook in het Perseus cluster.Astronomers discover dark matter bridge linking colliding galaxies:https://www.space.com/the-universe/astronomers-discover-dark-matter-bridge-linking-colliding-galaxies-this-is-the-missing-piece-weve-been-looking-forDirect Evidence of a Major Merger in the Perseus Cluster:https://arxiv.org/pdf/2405.00115Subaru telescoop:https://subarutelescope.org/en/SDSS:https://www.sdss.org/Hemelkalender 2025:https://www.vvs.be/bestel-de-hemelkalenderDe Zimmerman en Space podcast is gelicenseerd onder een Creative Commons CC0 1.0 licentie.http://creativecommons.org/publicdomain/zero/1.0

A fireside chat with Ajay Banga, President of the World Bank Group on Tuesday, October 1, 2024 in Hauck Auditorium, Hoover Institution.  Condoleezza Rice, Director of the Hoover Institution and 66th US Secretary of State, Arun Majumdar, Jay Precourt Professor and Dean of SDSS, and Peter Blair Henry, Class of 1984 Senior Fellow at Hoover, conduct a fireside chat with President Banga on the importance of the World Bank leading "informed risk-taking" to catalyze blended (public and private) finance to fund investment in development and accelerate the energy transition.  

U novom kabinetu Andreja Plenkovića sjede i predstavnici Domovinskog pokreta, stranke koja je donedavno sipala drvlja i kamenje po Plenkoviću i vladajućem HDZ-u. Sada su razmirice uklonjene i Domovinski pokret je dobio tri ministarske fotelje. Hoće li ulazak ove desničarske stranke promijeniti unutarnji i vanjskopolitički kurs Hrvatske. Zašto ženske udruge strahuju od smanjivanja prava žena? Nenad Kreizer razgovara s analitičarem Ivanom Rimcem i zagrebačkim dopisnikom Sinišom Bogdanićem. Von Nenad Kreizer.

Hrvatska u znaku Eurosonga: Baby Lasagna je u Zagrebu dočekan kao pobjednik. Milorad Pupovac kaže da Domovinski pokret njegovu stranku SDSS želi protjerati iz političkog života, a njega iz Hrvatske. Umro je pjesnik i književnik Luko Paljetak.

Nastavljaju se pregovori HDZ-a i Domovinskog pokreta oko sastavljanja saborske većine. Pokret i dalje odbija suradnju sa SDSS-om. Vesna Vučemilović poručila je da neće u koaliciju s SDP-om i Možemo. Suverenisti joj najavili izbacivanje iz stranke, ako ne posluša stranački vrh. SDP-ov Peđa Grbin i dalje pokušava sastaviti koaliciju i lijevih i desnih, iako nije jasno tko bi u tom slučaju sastavljao Vladu.

HDZ počinje intenzivne pregovore oko sastavljanja vlade. Glavni partner će, po svemu sudeći, biti Domovinski pokret. Milorad Pupovac ne zna hoće li njegov SDSS biti dio vladajuće većine no kaže da manjinci idu po principu: Svi ili nitko. U Jasenovcu je održana komemoracija povodom 79. obljetnice proboja logoraša.

你若是會當看著 可觀測宇宙 ê 邊界，毋知會按怎？你會當看著星系、星系、星系、kah 呃，類星體。類星體其實是遙遠 星系 光 iàⁿ-iàⁿ ê 中心區。這張 分佈圖 是為著欲予咱人類 tùi 看會著 ê 上大規模 ê 宇宙有閣較好 ê 理解，才做出來--ê。這是 ùi 2000 年 到 2020 年 ê SDSS 巡天計畫 ê 星系 kah 類星體 地圖，差不多是 可觀測宇宙 ê 邊界。這張 pizza 形 ê 影像是巡天觀測 ê 其中一區，這區包括 宇宙回溯時間（就是天體發出 ê 光行到地球 ê 時間）120 億年前、宇宙紅移 5 以內 ê 20 萬个 星系 kah 類星體。插圖 下面 ê 部份，差不多每一點攏代表一个 星系。較暗 ê 紅色光點，表示 紅移 較大，距離較遠。仝款，頂懸 ê 部份，嘛差不多每一點攏代表一个遙遠 ê 類星體，其中藍色光點是比紅色光點較近。Tī 足濟新發現 攏有清楚看著星系 kah 星系之間 ê 重力，會 kā 較近 ê 宇宙 堅凍 起來，比 遙遠宇宙 產生 閣較濟宇宙雲絲結構。 ——— 這是 NASA Astronomy Picture of the Day ê 台語文 podcast 原文版：https://apod.nasa.gov/ 台文版：https://apod.tw/ 今仔日 ê 文章： https://apod.tw/daily/20230705/ 影像來源 kah 版權：B. Ménard & N. Shtarkman 資料：SDSS, Planck, JHU, Sloan, NASA, ESA 音樂：P!SCO - 鼎鼎 聲優：阿錕 翻譯：An-Li Tsai (NCU) 原文：https://apod.nasa.gov/apod/ap230705.html Powered by Firstory Hosting

Tema: Este es el tercer de cuatro episodios que dedicaremos a indicar un trabajo de campo que es la observación con el ojo desnudo, binoculares y telescopios de estrellas representativas de las clases espectrales, como practica final a lo estudiado en los episodios precedentes sobre espectroscopia y clasificación estelar. En este capítulo las estrellas visibles entre junio y septiembre. Muy importante ver la página asociada con imágenes explicativas Enlaces: Web: Astrodidacta. Imágenes que ayudaran a la comprensión de los temas tratados Correo: astrodidacta2020@gmail.com Derechos de Música: Space Navigator por Sarah, The Illstrumentalist Derechos de Imagen Vega. SDSS

Reconstructing the extended structure of multiple sources strongly lensed by the ultra-massive elliptical galaxy SDSS J0100+1818 by A. Bolamperti et al. on Wednesday 30 November We study the total and baryonic mass distributions of the deflector SDSS J0100+1818 through a full strong lensing analysis. The system is composed by an ultra-massive early-type galaxy at $z=0.581$, with total stellar mass of $(1.5 pm 0.3) 10^{12}$ M$_odot$ and stellar velocity dispersion of ($450 pm 40$) km s$^{-1}$, surrounded by ten multiple images of three background sources, two of which spectroscopically confirmed at $z=1.880$. We take advantage of high-resolution HST photometry and VLT/X-shooter spectroscopy to measure the positions of the multiple images and perform a strong lensing study with the software GLEE. We test different total mass profiles for the lens and model the background sources first as point-like and then as extended objects. We successfully predict the positions of the observed multiple images and reconstruct over approximately 7200 HST pixels the complex surface brightness distributions of the sources. We measure the cumulative total mass profile of the lens and find a total mass value of $(9.1 pm 0.1) 10^{12}$ M$_odot$, within the Einstein radius of approximately 42 kpc, and stellar-over-total mass fractions ranging from ($49 pm 12$)%, at the half-light radius ($R_e = 9.3$ kpc) of the lens galaxy, to ($10 pm 2$)%, in the outer regions ($R = 70$kpc). These results suggest that the baryonic mass component of SDSS J0100+1818 is very concentrated in its core and that the lens early-type galaxy/group is immersed in a massive dark matter halo. This is consistent with what found in other ultra-high mass candidates at intermediate redshift. We measure also the physical sizes of the distant sources, resolving them down to a few hundreds of parsec. Finally, we quantify and discuss a relevant source of systematic uncertainties on the reconstructed sizes of background galaxies, associated to the adopted lens total mass model. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.16528v1

The radio structure of the γ -ray narrow-line Seyfert 1 galaxy SDSS J211852 96 - 073227 5 by Xi Shao et al. on Wednesday 30 November The $gamma$-ray narrow-line Seyfert 1 galaxies (NLS1s) can be considered to be the third class of $gamma$-ray active galactic nuclei possessing relativistic jets. In this paper, we present multi-band high resolution Very Long Baseline Array (VLBA) images of the $gamma$-ray NLS1, SDSS J211852.96$-$073227.5 (J2118$-$0732, $z=0.26$). We find a core-jet radio morphology and significant flux density variations in the radio core. The high brightness temperature estimated from VLBA images and core variability demonstrate that it exhibits substantial relativistic beaming effects. From considering radio emission in several bands, we find that the source has an inverted spectrum above 1 GHz but a steep spectrum at low frequencies from 74 MHz to 1 GHz; these may arise from the present activity and the old diffuse/extended emission, respectively. The core-jet morphology, significant flux density variations, and beaming effect make J2118$-$0732 resemble a blazar. Considering the low mass of its central black hole and ongoing merger environment, J2118$-$0732 may represent a low-mass, low-power counterpart of blazars, and may finally evolve to a blazar. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.16705v1

Reconstructing the extended structure of multiple sources strongly lensed by the ultra-massive elliptical galaxy SDSS J0100+1818 by A. Bolamperti et al. on Wednesday 30 November We study the total and baryonic mass distributions of the deflector SDSS J0100+1818 through a full strong lensing analysis. The system is composed by an ultra-massive early-type galaxy at $z=0.581$, with total stellar mass of $(1.5 pm 0.3) 10^{12}$ M$_odot$ and stellar velocity dispersion of ($450 pm 40$) km s$^{-1}$, surrounded by ten multiple images of three background sources, two of which spectroscopically confirmed at $z=1.880$. We take advantage of high-resolution HST photometry and VLT/X-shooter spectroscopy to measure the positions of the multiple images and perform a strong lensing study with the software GLEE. We test different total mass profiles for the lens and model the background sources first as point-like and then as extended objects. We successfully predict the positions of the observed multiple images and reconstruct over approximately 7200 HST pixels the complex surface brightness distributions of the sources. We measure the cumulative total mass profile of the lens and find a total mass value of $(9.1 pm 0.1) 10^{12}$ M$_odot$, within the Einstein radius of approximately 42 kpc, and stellar-over-total mass fractions ranging from ($49 pm 12$)%, at the half-light radius ($R_e = 9.3$ kpc) of the lens galaxy, to ($10 pm 2$)%, in the outer regions ($R = 70$kpc). These results suggest that the baryonic mass component of SDSS J0100+1818 is very concentrated in its core and that the lens early-type galaxy/group is immersed in a massive dark matter halo. This is consistent with what found in other ultra-high mass candidates at intermediate redshift. We measure also the physical sizes of the distant sources, resolving them down to a few hundreds of parsec. Finally, we quantify and discuss a relevant source of systematic uncertainties on the reconstructed sizes of background galaxies, associated to the adopted lens total mass model. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.16528v1

The radio structure of the γ -ray narrow-line Seyfert 1 galaxy SDSS J211852 96 - 073227 5 by Xi Shao et al. on Wednesday 30 November The $gamma$-ray narrow-line Seyfert 1 galaxies (NLS1s) can be considered to be the third class of $gamma$-ray active galactic nuclei possessing relativistic jets. In this paper, we present multi-band high resolution Very Long Baseline Array (VLBA) images of the $gamma$-ray NLS1, SDSS J211852.96$-$073227.5 (J2118$-$0732, $z=0.26$). We find a core-jet radio morphology and significant flux density variations in the radio core. The high brightness temperature estimated from VLBA images and core variability demonstrate that it exhibits substantial relativistic beaming effects. From considering radio emission in several bands, we find that the source has an inverted spectrum above 1 GHz but a steep spectrum at low frequencies from 74 MHz to 1 GHz; these may arise from the present activity and the old diffuse/extended emission, respectively. The core-jet morphology, significant flux density variations, and beaming effect make J2118$-$0732 resemble a blazar. Considering the low mass of its central black hole and ongoing merger environment, J2118$-$0732 may represent a low-mass, low-power counterpart of blazars, and may finally evolve to a blazar. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.16705v1

Association of Optical, Ultraviolet and Soft X-ray excess Emissions in AGNs by D. Nour et al. on Tuesday 29 November Soft X-ray emission (0.5--2.0 keV) plays a pivotal role in regulating the optical and UV emission in the AGNs. We collected a sample of 1811 AGNs from the SDSS database and obtained various parameters of Balmer lines, optical continuum, MgII line & UV continuum and studied their dependencies on soft X-ray luminosity. Based on the linear regression analysis, we found that FWHM$_{text{MgII}}$ $propto$ FWHM$_{text{H}beta}^{0.554}$ suggesting that UV emission is arising from a region relatively outside the broad line region (BLR) associated to the H$beta$ emission and found a strong correlation between optical and UV luminosities (L$_{text{MgII}}$ $propto$ L$_{text{H}beta}^{0.822}$). It was noticed that the dependency of optical continuum luminosities on soft excess changes with the redshift (L$_{text{X}}$ $propto$ L$^{0.596}_{5100text{AA}}$ for z < 0.5 and L$_{text{X}}$ $propto$ L$^{0.429}_{5100text{AA}}$ for z > 0.5). The FWHM components of H${beta}$ and MgII core components were found to be virialized and is not affected by the soft excess emission whereas the wings of MgII display a dependency. We estimated a relation viz. L$_{text{X}}$ $propto$L$^{0.520}_{3000text{AA}}$ FWHM$^{0.525}_{text{MgII}}$ and found to be well in agreement with a proposed physical scenario. All the derived relations were used to understand the inter-modulating association of the BLR and disc in the AGNs. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.15077v1

Tema: Este es el tercer de cuatro episodios que dedicaremos a indicar un trabajo de campo que es la observación con el ojo desnudo, binoculares y telescopios de estrellas representativas de las clases espectrales, como practica final a lo estudiado en los episodios precedentes sobre espectroscopia y clasificación estelar. En este capítulo las estrellas visibles entre marzo y junio. Muy importante ver la página asociada con imágenes explicativas Enlaces: Web: Astrodidacta. Imágenes que ayudaran a la comprensión de los temas tratados Correo: astrodidacta2020@gmail.com Derechos de Música: Space Navigator por Sarah, The Illstrumentalist Derechos de Imagen Adhafera. SDSS

Association of Optical, Ultraviolet and Soft X-ray excess Emissions in AGNs by D. Nour et al. on Monday 28 November Soft X-ray emission (0.5--2.0 keV) plays a pivotal role in regulating the optical and UV emission in the AGNs. We collected a sample of 1811 AGNs from the SDSS database and obtained various parameters of Balmer lines, optical continuum, MgII line & UV continuum and studied their dependencies on soft X-ray luminosity. Based on the linear regression analysis, we found that FWHM$_{text{MgII}}$ $propto$ FWHM$_{text{H}beta}^{0.554}$ suggesting that UV emission is arising from a region relatively outside the broad line region (BLR) associated to the H$beta$ emission and found a strong correlation between optical and UV luminosities (L$_{text{MgII}}$ $propto$ L$_{text{H}beta}^{0.822}$). It was noticed that the dependency of optical continuum luminosities on soft excess changes with the redshift (L$_{text{X}}$ $propto$ L$^{0.596}_{5100text{AA}}$ for z < 0.5 and L$_{text{X}}$ $propto$ L$^{0.429}_{5100text{AA}}$ for z > 0.5). The FWHM components of H${beta}$ and MgII core components were found to be virialized and is not affected by the soft excess emission whereas the wings of MgII display a dependency. We estimated a relation viz. L$_{text{X}}$ $propto$L$^{0.520}_{3000text{AA}}$ FWHM$^{0.525}_{text{MgII}}$ and found to be well in agreement with a proposed physical scenario. All the derived relations were used to understand the inter-modulating association of the BLR and disc in the AGNs. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.15077v1

Nuclear Activity in the Low Metallicity Dwarf Galaxy SDSS J0944-0038: A Glimpse into the Primordial Universe by Michael Reefe et al. on Friday 25 November Local low metallicity dwarf galaxies are relics of the early universe and hold clues into the origins of supermassive black holes (SMBHs). In recent work, coronal lines have been used to unveil a population of candidate accreting black holes in dwarf galaxies with gas phase metallicities and stellar masses well below the host galaxies of any previously known AGNs. Using MUSE/VLT observations, we report the detection of [Fe X] $lambda$6374 coronal line emission and a broad H$alpha$ line in the nucleus of SDSS J094401.87$-$003832.1, a nearby ($z=0.0049$) metal poor dwarf galaxy at least fifty times less massive than the LMC. The [Fe X] $lambda$6374 emission is compact and centered on the brightest nuclear source, with a spatial extent of $approx$100 pc. The [Fe X] luminosity is $approx 10^{37}$ erg s$^{-1}$, within the range seen in previously identified AGNs in the dwarf galaxy population. This line has never been observed in gas ionized by hot stars. While it can be produced in supernova ejecta, the [Fe X] flux from SDSS J094401.87$-$003832.1 has persisted over the ~19 year time period between the SDSS and MUSE observations, ruling out supernovae as the origin for the emission. The FWHM of the broad component of the H$alpha$ line is $446 pm 17$ km s$^{-1}$ and its luminosity is $approx 1.5times10^{38}$ erg s$^{-1}$, lower than the broad line luminosities of previously identified low mass broad line AGNs. These observations, together with previously reported multi-wavelength observations, can most plausibly be explained by the presence of an accreting intermediate mass black hole in a primordial galaxy analog. However, we cannot rule out the possibility that current stellar population models of metal poor stars significantly under-predict the stellar ionizing photon flux, and that metal poor stars can produce an extreme ionizing spectrum similar to that produced by AGNs. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.13179v1

Nuclear Activity in the Low Metallicity Dwarf Galaxy SDSS J0944-0038: A Glimpse into the Primordial Universe by Michael Reefe et al. on Thursday 24 November Local low metallicity dwarf galaxies are relics of the early universe and hold clues into the origins of supermassive black holes (SMBHs). In recent work, coronal lines have been used to unveil a population of candidate accreting black holes in dwarf galaxies with gas phase metallicities and stellar masses well below the host galaxies of any previously known AGNs. Using MUSE/VLT observations, we report the detection of [Fe X] $lambda$6374 coronal line emission and a broad H$alpha$ line in the nucleus of SDSS J094401.87$-$003832.1, a nearby ($z=0.0049$) metal poor dwarf galaxy at least fifty times less massive than the LMC. The [Fe X] $lambda$6374 emission is compact and centered on the brightest nuclear source, with a spatial extent of $approx$100 pc. The [Fe X] luminosity is $approx 10^{37}$ erg s$^{-1}$, within the range seen in previously identified AGNs in the dwarf galaxy population. This line has never been observed in gas ionized by hot stars. While it can be produced in supernova ejecta, the [Fe X] flux from SDSS J094401.87$-$003832.1 has persisted over the ~19 year time period between the SDSS and MUSE observations, ruling out supernovae as the origin for the emission. The FWHM of the broad component of the H$alpha$ line is $446 pm 17$ km s$^{-1}$ and its luminosity is $approx 1.5times10^{38}$ erg s$^{-1}$, lower than the broad line luminosities of previously identified low mass broad line AGNs. These observations, together with previously reported multi-wavelength observations, can most plausibly be explained by the presence of an accreting intermediate mass black hole in a primordial galaxy analog. However, we cannot rule out the possibility that current stellar population models of metal poor stars significantly under-predict the stellar ionizing photon flux, and that metal poor stars can produce an extreme ionizing spectrum similar to that produced by AGNs. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.13179v1

Asteroseismology of the pulsating extremely low-mass white dwarf SDSS J111215 82+111745 0: a model with p -mode pulsations consistent with the observations by Jie Su et al. on Wednesday 23 November SDSS J111215.82+111745.0 is the second pulsating extremely low-mass white dwarf discovered. Two short-period pulsations, 107.56 and 134.275 s, were detected on this star, which would be the first observed pressure mode ($p$-mode) pulsations observed on a white dwarf. While the two potential $p$-modes have yet to be confirmed, they make SDSS J111215.82+111745.0 an interesting object. In this work, we analyzed the whole set of seven periods observed on SDSS J111215.82+111745.0. We adopt three independent period-spacing tests to reveal a roughly 93.4 s mean period spacing of $ell=1$ $g$-modes, which gives added credence to the $ell=1$ identifications. Then we perform asteroseismic modeling for this star, in which the H chemical profile is taken as a variable. The stellar parameters $M=0.1650pm0.0137$ $M_odot$ and $T_mathrm{eff}=9750pm560$ K are determined from the best-fit model and the H/He chemical profiles are also defined. The two suspected $p$-modes are also well represented in the best-fit model, and both the stellar parameters and the pulsation frequencies are in good agreement with the values derived from spectroscopy. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.12011v1

CLASS Survey Description: Coronal Line Needles in the SDSS Haystack by Michael Reefe et al. on Wednesday 23 November Coronal lines are a powerful, yet poorly understood, tool to identify and characterize Active Galactic Nuclei (AGNs). There have been few large scale surveys of coronal lines in the general galaxy population in the literature so far. Using a novel pre-selection technique with a flux-to-RMS ratio $F$, followed by Markov-Chain Monte Carlo (MCMC) fitting, we searched for the full suite of 20 coronal lines in the optical spectra of almost 1 million galaxies from the Sloan Digital Sky Survey (SDSS) Data Release 8. We present a catalog of the emission line parameters for the resulting 258 galaxies with detections. The Coronal Line Activity Spectroscopic Survey (CLASS) includes line properties, host galaxy properties, and selection criteria for all galaxies in which at least one line is detected. This comprehensive study reveals that a significant fraction of coronal line activity is missed in past surveys based on a more limited set of coronal lines; $sim$60% of our sample do not display the more widely surveyed [Fe X] $lambda$6374. In addition, we discover a strong correlation between coronal line and WISE W2 luminosities, suggesting that the mid-infrared flux can be used to predict coronal line fluxes. For each line we also provide a confidence level that the line is present, generated by a novel neural network, trained on fully simulated data. We find that after training the network to detect individual lines using 100,000 simulated spectra, we achieve an overall true positive rate of 75.49% and a false positive rate of only 3.96%. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.11882v1

Reconstructing and Classifying SDSS DR16 Galaxy Spectra with Machine-Learning and Dimensionality Reduction Algorithms by Felix Pat et al. on Wednesday 23 November Optical spectra of galaxies and quasars from large cosmological surveys are used to measure redshifts and infer distances. They are also rich with information on the intrinsic properties of these astronomical objects. However, their physical interpretation can be challenging due to the substantial number of degrees of freedom, various sources of noise, and degeneracies between physical parameters that cause similar spectral characteristics. To gain deeper insights into these degeneracies, we apply two unsupervised machine learning frameworks to a sample from the Sloan Digital Sky Survey data release 16 (SDSS DR16). The first framework is a Probabilistic Auto-Encoder (PAE), a two-stage deep learning framework consisting of a data compression stage from 1000 elements to 10 parameters and a density estimation stage. The second framework is a Uniform Manifold Approximation and Projection (UMAP), which we apply to both the uncompressed and compressed data. Exploring across regions on the compressed data UMAP, we construct sequences of stacked spectra which show a gradual transition from star-forming galaxies with narrow emission lines and blue spectra to passive galaxies with absorption lines and red spectra. Focusing on galaxies with broad emission lines produced by quasars, we find a sequence with varying levels of obscuration caused by cosmic dust. The experiments we present here inform future applications of neural networks and dimensionality reduction algorithms for large astronomical spectroscopic surveys. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.11783v1

Consistent and simultaneous modelling of galaxy clustering and galaxy-galaxy lensing with Subhalo Abundance Matching by Sergio Contreras et al. on Wednesday 23 November The spatial distribution of galaxies and their gravitational lensing signal offer complementary tests of galaxy formation physics and cosmology. However, their synergy can only be fully exploited if both probes are modelled accurately and consistently. In this paper, we demonstrate that this can be achieved using an extension of Subhalo Abundance Matching, dubbed SHAMe. Specifically, we use mock catalogues built from the TNG300 hydrodynamical simulation to show that SHAMe can simultaneously model the multipoles of the redshift-space galaxy correlation function and galaxy-galaxy lensing, without noticeable bias within the statistical sampling uncertainties of a SDSS volume and on scales r = [0.6-30] Mpc/h. Modelling the baryonic processes in galaxy-galaxy lensing with a baryonification scheme allows SHAMe's range of validity to be extended to r = [0.1-30] Mpc/h. Remarkably, our model achieves this level of precision with just five free parameters beyond those describing the baryonification model. At fixed cosmology, we find that galaxy-galaxy lensing provides a general consistency test but little additional information on galaxy modelling parameters beyond that encoded in the redshift-space multipoles. It does, however, improve constraints if only the projected correlation function is available, as in surveys with only photometric redshifts. We expect SHAMe to have a higher fidelity across a wider range of scales than more traditional methods such as Halo Occupation Distribution modelling. Thus it should provide a significantly more powerful and more robust tool for analysing next-generation large-scale surveys. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.11745v1

Asteroseismology of the pulsating extremely low-mass white dwarf SDSS J111215 82+111745 0: a model with p -mode pulsations consistent with the observations by Jie Su et al. on Tuesday 22 November SDSS J111215.82+111745.0 is the second pulsating extremely low-mass white dwarf discovered. Two short-period pulsations, 107.56 and 134.275 s, were detected on this star, which would be the first observed pressure mode ($p$-mode) pulsations observed on a white dwarf. While the two potential $p$-modes have yet to be confirmed, they make SDSS J111215.82+111745.0 an interesting object. In this work, we analyzed the whole set of seven periods observed on SDSS J111215.82+111745.0. We adopt three independent period-spacing tests to reveal a roughly 93.4 s mean period spacing of $ell=1$ $g$-modes, which gives added credence to the $ell=1$ identifications. Then we perform asteroseismic modeling for this star, in which the H chemical profile is taken as a variable. The stellar parameters $M=0.1650pm0.0137$ $M_odot$ and $T_mathrm{eff}=9750pm560$ K are determined from the best-fit model and the H/He chemical profiles are also defined. The two suspected $p$-modes are also well represented in the best-fit model, and both the stellar parameters and the pulsation frequencies are in good agreement with the values derived from spectroscopy. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.12011v1

Consistent and simultaneous modelling of galaxy clustering and galaxy-galaxy lensing with Subhalo Abundance Matching by Sergio Contreras et al. on Tuesday 22 November The spatial distribution of galaxies and their gravitational lensing signal offer complementary tests of galaxy formation physics and cosmology. However, their synergy can only be fully exploited if both probes are modelled accurately and consistently. In this paper, we demonstrate that this can be achieved using an extension of Subhalo Abundance Matching, dubbed SHAMe. Specifically, we use mock catalogues built from the TNG300 hydrodynamical simulation to show that SHAMe can simultaneously model the multipoles of the redshift-space galaxy correlation function and galaxy-galaxy lensing, without noticeable bias within the statistical sampling uncertainties of a SDSS volume and on scales r = [0.6-30] Mpc/h. Modelling the baryonic processes in galaxy-galaxy lensing with a baryonification scheme allows SHAMe's range of validity to be extended to r = [0.1-30] Mpc/h. Remarkably, our model achieves this level of precision with just five free parameters beyond those describing the baryonification model. At fixed cosmology, we find that galaxy-galaxy lensing provides a general consistency test but little additional information on galaxy modelling parameters beyond that encoded in the redshift-space multipoles. It does, however, improve constraints if only the projected correlation function is available, as in surveys with only photometric redshifts. We expect SHAMe to have a higher fidelity across a wider range of scales than more traditional methods such as Halo Occupation Distribution modelling. Thus it should provide a significantly more powerful and more robust tool for analysing next-generation large-scale surveys. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.11745v1

CLASS Survey Description: Coronal Line Needles in the SDSS Haystack by Michael Reefe et al. on Tuesday 22 November Coronal lines are a powerful, yet poorly understood, tool to identify and characterize Active Galactic Nuclei (AGNs). There have been few large scale surveys of coronal lines in the general galaxy population in the literature so far. Using a novel pre-selection technique with a flux-to-RMS ratio $F$, followed by Markov-Chain Monte Carlo (MCMC) fitting, we searched for the full suite of 20 coronal lines in the optical spectra of almost 1 million galaxies from the Sloan Digital Sky Survey (SDSS) Data Release 8. We present a catalog of the emission line parameters for the resulting 258 galaxies with detections. The Coronal Line Activity Spectroscopic Survey (CLASS) includes line properties, host galaxy properties, and selection criteria for all galaxies in which at least one line is detected. This comprehensive study reveals that a significant fraction of coronal line activity is missed in past surveys based on a more limited set of coronal lines; $sim$60% of our sample do not display the more widely surveyed [Fe X] $lambda$6374. In addition, we discover a strong correlation between coronal line and WISE W2 luminosities, suggesting that the mid-infrared flux can be used to predict coronal line fluxes. For each line we also provide a confidence level that the line is present, generated by a novel neural network, trained on fully simulated data. We find that after training the network to detect individual lines using 100,000 simulated spectra, we achieve an overall true positive rate of 75.49% and a false positive rate of only 3.96%. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.11882v1

Reconstructing and Classifying SDSS DR16 Galaxy Spectra with Machine-Learning and Dimensionality Reduction Algorithms by Felix Pat et al. on Tuesday 22 November Optical spectra of galaxies and quasars from large cosmological surveys are used to measure redshifts and infer distances. They are also rich with information on the intrinsic properties of these astronomical objects. However, their physical interpretation can be challenging due to the substantial number of degrees of freedom, various sources of noise, and degeneracies between physical parameters that cause similar spectral characteristics. To gain deeper insights into these degeneracies, we apply two unsupervised machine learning frameworks to a sample from the Sloan Digital Sky Survey data release 16 (SDSS DR16). The first framework is a Probabilistic Auto-Encoder (PAE), a two-stage deep learning framework consisting of a data compression stage from 1000 elements to 10 parameters and a density estimation stage. The second framework is a Uniform Manifold Approximation and Projection (UMAP), which we apply to both the uncompressed and compressed data. Exploring across regions on the compressed data UMAP, we construct sequences of stacked spectra which show a gradual transition from star-forming galaxies with narrow emission lines and blue spectra to passive galaxies with absorption lines and red spectra. Focusing on galaxies with broad emission lines produced by quasars, we find a sequence with varying levels of obscuration caused by cosmic dust. The experiments we present here inform future applications of neural networks and dimensionality reduction algorithms for large astronomical spectroscopic surveys. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.11783v1

Consistent and simultaneous modelling of galaxy clustering and galaxy-galaxy lensing with Subhalo Abundance Matching by Sergio Contreras et al. on Tuesday 22 November The spatial distribution of galaxies and their gravitational lensing signal offer complementary tests of galaxy formation physics and cosmology. However, their synergy can only be fully exploited if both probes are modelled accurately and consistently. In this paper, we demonstrate that this can be achieved using an extension of Subhalo Abundance Matching, dubbed SHAMe. Specifically, we use mock catalogues built from the TNG300 hydrodynamical simulation to show that SHAMe can simultaneously model the multipoles of the redshift-space galaxy correlation function and galaxy-galaxy lensing, without noticeable bias within the statistical sampling uncertainties of a SDSS volume and on scales r = [0.6-30] Mpc/h. Modelling the baryonic processes in galaxy-galaxy lensing with a baryonification scheme allows SHAMe's range of validity to be extended to r = [0.1-30] Mpc/h. Remarkably, our model achieves this level of precision with just five free parameters beyond those describing the baryonification model. At fixed cosmology, we find that galaxy-galaxy lensing provides a general consistency test but little additional information on galaxy modelling parameters beyond that encoded in the redshift-space multipoles. It does, however, improve constraints if only the projected correlation function is available, as in surveys with only photometric redshifts. We expect SHAMe to have a higher fidelity across a wider range of scales than more traditional methods such as Halo Occupation Distribution modelling. Thus it should provide a significantly more powerful and more robust tool for analysing next-generation large-scale surveys. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.11745v1

Understanding the role of morphology and environment on the dynamical evolution of isolated galaxy triplets by P. Vásquez-Bustos et al. on Tuesday 22 November The environment where galaxies reside affects their evolutionary histories. Galaxy triplets (systems composed of three physically bound galaxies) constitute one of simplest group of galaxies and are therefore excellent laboratories to study evolutionary mechanisms where effects of the environment are minimal. We present a statistical study of the dynamical properties of isolated galaxy triplets as a function of their local and large scale environments. To explore the connection of the dynamical evolution on the systems with the evolution of the galaxies composing the triplets, we consider observational properties as morphology and star formation rate (SFR). We used the SDSS-based catalog of Isolated Triplets (SIT), which contains 315 triplets. We classified each triplet according to galaxy morphologies and defined a parameter $Q_{trip}$ to quantify the total local tidal strengths in the systems. To quantify the dynamical stage of the system we used the parameters harmonic radius, $R_H$, velocity dispersion, $sigma_{vr}$, crossing time, $H_0t_c$, and virial mass, $M_{vir}$. Triplets composed of three early type galaxies present smallest $R_H$, indicating that they are in general more compact than triplets with one or more late type galaxies. Among triplets with low values of $R_H$ and $H_0t_c$, SIT triplets with $Q_{trip}$-2 show compact configurations due to interactions within the system, such as on-going mergers. We found that there is no dominant galaxy in triplets in terms of properties of stellar populations such as global colour and SFR. Moreover, the global SFR in isolated triplets composed of two or more early-type galaxies increases with the stellar mass ratio of the galaxies with respect to the central galaxy, therefore the system is globally 'rejuvenated'. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.10290v1

Understanding the role of morphology and environment on the dynamical evolution of isolated galaxy triplets by P. Vásquez-Bustos et al. on Monday 21 November The environment where galaxies reside affects their evolutionary histories. Galaxy triplets (systems composed of three physically bound galaxies) constitute one of simplest group of galaxies and are therefore excellent laboratories to study evolutionary mechanisms where effects of the environment are minimal. We present a statistical study of the dynamical properties of isolated galaxy triplets as a function of their local and large scale environments. To explore the connection of the dynamical evolution on the systems with the evolution of the galaxies composing the triplets, we consider observational properties as morphology and star formation rate (SFR). We used the SDSS-based catalog of Isolated Triplets (SIT), which contains 315 triplets. We classified each triplet according to galaxy morphologies and defined a parameter $Q_{trip}$ to quantify the total local tidal strengths in the systems. To quantify the dynamical stage of the system we used the parameters harmonic radius, $R_H$, velocity dispersion, $sigma_{vr}$, crossing time, $H_0t_c$, and virial mass, $M_{vir}$. Triplets composed of three early type galaxies present smallest $R_H$, indicating that they are in general more compact than triplets with one or more late type galaxies. Among triplets with low values of $R_H$ and $H_0t_c$, SIT triplets with $Q_{trip}$-2 show compact configurations due to interactions within the system, such as on-going mergers. We found that there is no dominant galaxy in triplets in terms of properties of stellar populations such as global colour and SFR. Moreover, the global SFR in isolated triplets composed of two or more early-type galaxies increases with the stellar mass ratio of the galaxies with respect to the central galaxy, therefore the system is globally 'rejuvenated'. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.10290v1

Understanding the role of morphology and environment on the dynamical evolution of isolated galaxy triplets by P. Vásquez-Bustos et al. on Monday 21 November The environment where galaxies reside affects their evolutionary histories. Galaxy triplets (systems composed of three physically bound galaxies) constitute one of simplest group of galaxies and are therefore excellent laboratories to study evolutionary mechanisms where effects of the environment are minimal. We present a statistical study of the dynamical properties of isolated galaxy triplets as a function of their local and large scale environments. To explore the connection of the dynamical evolution on the systems with the evolution of the galaxies composing the triplets, we consider observational properties as morphology and star formation rate (SFR). We used the SDSS-based catalog of Isolated Triplets (SIT), which contains 315 triplets. We classified each triplet according to galaxy morphologies and defined a parameter $Q_{trip}$ to quantify the total local tidal strengths in the systems. To quantify the dynamical stage of the system we used the parameters harmonic radius, $R_H$, velocity dispersion, $sigma_{vr}$, crossing time, $H_0t_c$, and virial mass, $M_{vir}$. Triplets composed of three early type galaxies present smallest $R_H$, indicating that they are in general more compact than triplets with one or more late type galaxies. Among triplets with low values of $R_H$ and $H_0t_c$, SIT triplets with $Q_{trip}$-2 show compact configurations due to interactions within the system, such as on-going mergers. We found that there is no dominant galaxy in triplets in terms of properties of stellar populations such as global colour and SFR. Moreover, the global SFR in isolated triplets composed of two or more early-type galaxies increases with the stellar mass ratio of the galaxies with respect to the central galaxy, therefore the system is globally 'rejuvenated'. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.10290v1

Tema: Este es el segundo de cuatro episodios que dedicaremos a indicar un trabajo de campo que es la observación con el ojo desnudo, binoculares y telescopios de estrellas representativas de las clases espectrales, como practica final a lo estudiado en los episodios precedentes sobre espectroscopia y clasificación estelar. En este capítulo las estrellas visibles entre diciembre y marzo. Muy importante ver la página asociada con imágenes explicativas Enlaces: Web: Astrodidacta. Imágenes que ayudaran a la comprensión de los temas tratados Correo: astrodidacta2020@gmail.com Derechos de Música: Space Navigator por Sarah, The Illstrumentalist Derechos de Imagen Betelgeuse. SDSS

Tema: Este es el primero de cuatro episodios que dedicaremos a un trabajo de campo que es la observación con el ojo desnudo, binoculares y telescopios de estrellas representativas de las clases espectrales, como práctica final a lo estudiado en los episodios precedentes sobre espectroscopia y clasificación estelar. En este capítulo las estrellas visibles entre septiembre y diciembre. Muy importante ver la página asociada con imágenes explicativas. Enlaces: Web: Astrodidacta. Imágenes que ayudaran a la comprensión de los temas tratados Correo: astrodidacta2020@gmail.com Derechos de Música: Space Navigator por Sarah, The Illstrumentalist Derechos de Imagen Mirach. SDSS

Aging of galaxies along the morphological sequence, marked by bulge growth and disk quenching by Louis Quilley et al. on Tuesday 18 October We revisit the color bimodality of galaxies using the extensive EFIGI morphological classification of nearby galaxies. The galaxy SDSS images in the g, r and i bands are decomposed as bulge+disk using SourceXtractor++. The spectral energy distributions made of our gri photometry complemented with GALEX NUV are fitted with ZPEG in order to estimate the stellar masses and specific star formations rates (sSFR) of whole galaxies as well as their bulge and disk components. The absolute NUV-r color versus stellar mass diagram shows a continuous relationship between the present sSFR of galaxies and their stellar mass, that spans all morphological types of the Hubble sequence. Irregular galaxies to Sab spirals make up the Blue Cloud, the Green Plain (formerly Valley) is made up of early-type spirals (S0a-Sa) while the Red Sequence contains all lenticular and elliptical galaxies, with systematically higher masses for the ellipticals. Galaxies across the Green Plain undergo a marked growth by a factor 2 to 3 in their bulge-to-total mass ratio and a systematic profile change from pseudo to classical bulges, as well as a significant reddening interpreted as star formation fading in their disks. Therefore, the Green Plain is a transition region, and we exclude a predominantly quick transit due to rapid quenching. We suggest that tracers of increased star formation (bright HII regions, spiral arms, flocculence) determine the limited scatter of the Main Sequence of star-forming galaxies. The high frequency of bars for all spirals as well as the stronger spiral arms and flocculence in the knee of the Green Plain suggest that internal dynamics, likely triggered by flybys or mergers, may be the key to the bulge growth of massive disk galaxies, marker of the aging of galaxies from star forming to quiescence. The Hubble sequence can then be considered as an inverse sequence of galaxy physical evolution. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2206.04707v2

Polar Dust Emission in Quasar IR SEDs and Its Correlation with Narrow Line Regions by Jianwei Lyu et al. on Monday 17 October Polar dust has been found to play an important role in the mid-infrared emission of nearby Seyfert nuclei. If and how often polar dust exists among the quasar population is unknown due to the lack of spatially-resolved observations. In this Letter, we report correlations between the prominence of AGN forbidden line emission (commonly associated with the narrow line region) and the dust mid-IR energy output among the archetypal Palomar-Green quasar sample and other bright type-1 AGNs drawn from the SDSS, Spitzer and WISE archives. The AGN mid-IR color differences traced by WISE W2 ($sim4.6 mu m$)$-$W3 ($sim12 mu m$) and W2 ($sim4.6 mu m$)$-$W4 ($sim22 mu m$), and near-IR to mid-IR SEDs constrained with 2MASS, WISE and Spitzer data have clear trends with the relative strength of the forbidden line regions traced by the optical OIII and mid-IR OIV emission lines. These observations indicate that, where the lines are strong, a large fraction of the AGN emission at $lambdagtrsim5 mu$m comes from dust in the forbidden line regions. We find that the widely quoted universal AGN template is a result of averaging quasar SEDs with different levels of polar dust emission above the torus output and that the typical intrinsic IR SED of compact torus dust emission alone falls with increasing wavelength past 5 $mu$m (in $nu F_nu$). In addition, the association of polar dust with the forbidden lines suggests an alternative to the receding torus hypothesis for the decrease in infrared output with increasing AGN luminosity. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2210.08037v1

A Transient `Changing-Look' AGN Resolved on Month Timescales From First-Year SDSS-V Data by Grisha Zeltyn et al. on Sunday 16 October We report the discovery of a new `changing-look' active galactic nucleus (CLAGN) event, in the quasar SDSS J162829.17+432948.5 at z=0.2603, identified through repeat spectroscopy from the fifth Sloan Digital Sky Survey (SDSS-V). Optical photometry taken during 2020-2021 shows a dramatic dimming of ${Delta}$g${approx}$1 mag, followed by a rapid recovery on a timescale of several months, with the ${lesssim}$2 month period of rebrightening captured in new SDSS-V and Las Cumbres Observatory spectroscopy. This is one of the fastest CLAGN transitions observed to date. Archival observations suggest that the object experienced a much more gradual dimming over the period of 2011-2013. Our spectroscopy shows that the photometric changes were accompanied by dramatic variations in the quasar-like continuum and broad-line emission. The excellent agreement between the pre- and post-dip photometric and spectroscopic appearances of the source, as well as the fact that the dimmest spectra can be reproduced by applying a single extinction law to the brighter spectral states, favor a variable line-of-sight obscuration as the driver of the observed transitions. Such an interpretation faces several theoretical challenges, and thus an alternative accretion-driven scenario cannot be excluded. The recent events observed in this quasar highlight the importance of spectroscopic monitoring of large AGN samples on weeks-to-months timescales, which the SDSS-V is designed to achieve. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2210.07258v1

A Blueprint for the Milky Way's Stellar Populations IV Spectrum-based Empirical Corrections and the Galactic Starburst Sequence by Deokkeun An et al. on Sunday 16 October We continue our series of papers on phase-space distributions of stars in the Milky Way based on photometrically derived metallicities and Gaia astrometry, with a focus on the halo-disk interface in the local volume. To exploit various photometric databases, we develop a method of empirically calibrating synthetic stellar spectra based on a comparison with observations of stellar sequences and individual stars in SDSS, SMSS, and PS1, overcoming band-specific corrections employed in our previous work. In addition, photometric zero-point corrections are derived to provide an internally consistent photometric system with a spatially uniform metallicity zero point. Based on our phase-space diagrams, we find a strikingly narrow sequence in the rotational velocity ($v_phi$) versus metallicity ([Fe/H]) space for a sample of high proper-motion stars ($>25$ mas yr$^{-1}$), which runs along the Gaia Sausage/Enceladus (GSE) and the Splash sub-structures, and is connected to the disk. Notably, a rapid increase of $v_phi$ from a nearly zero net rotation to $200$ km s$^{-1}$ within a narrow metallicity interval ($-0.8 < {rm [Fe/H]} < -0.2$) suggests that these stars were formed on a short gas-depletion time scale. Based on measurements of a scale height and length, we argue that they are distinct from stars dynamically heated by mergers, and are the relics formed during the starburst when the young Milky Way encountered the gas-rich GSE merger. The chain of high proper-motion stars, which we dub the Galactic Starburst Sequence (GSS), provides evidence that the post-merger metal-enriched gas settled onto the disk. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2210.07542v1

Cold gas mass measurements for the era of large optical spectroscopic surveys by Dirk Scholte et al. on Wednesday 12 October Gas plays an important role in many processes in galaxy formation and evolution, but quantifying the importance of gas has been hindered by the challenge to measure gas masses for large samples of galaxies. Datasets of direct atomic and molecular gas measurements are sufficient to establish simple scaling relations, but often not large enough to quantify three-parameter relations, or second order dependencies. As an alternative approach, we derive here indirect cold gas measurements from optical emission lines using photoionization models for galaxies in the SDSS main galaxy sample and the PHANGS-MUSE survey. We calibrate the gas surface density measurements using xCOLD GASS and PHANGS-ALMA molecular gas measurements to ensure our measurements are reliable. We demonstrate the importance of taking into account the scale-dependence of the relation between optical depth ($tau_V$) and gas surface density ($Sigma_{gas}$) and provide a general prescription to estimate $Sigma_{gas}$ from $tau_V$, metallicity and the dust-to-metal ratio, at any arbitrary physical resolution. To demonstrate that the indirect cold gas masses are accurate enough to quantify the role of gas in galaxy evolution, we study the mass-metallicity relation (MZR) of SDSS galaxies and show that as a third parameter, gas mass is better than SFR at reducing the scatter of the relation, as predicted by models and simulations. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2210.05683v1

Galaxy Manifold: Characterizing and understanding galaxies with two parameters by Suchetha Cooray et al. on Wednesday 12 October We report the discovery of a two-dimensional Galaxy Manifold within the multi-dimensional luminosity space of local galaxies. The multi-dimensional luminosity space is constructed using 11 bands that span from far ultraviolet to near-infrared for redshift < 0.1 galaxies observed with GALEX, SDSS, and UKIDSS. The two latent parameters are sufficient to express 93.2% of the variance in the galaxy sample, suggesting that this Galaxy Manifold is one of the most efficient representations of galaxies. The transformation between the observed luminosities and the manifold parameters as an analytic mapping is provided. The manifold representation provides accurate (85%) morphological classifications with a simple linear boundary, and galaxy properties can be estimated with minimal scatter (0.12 dex and 0.04 dex for star formation rate and stellar mass, respectively) by calibrating with the two-dimensional manifold location. Under the assumption that the manifold expresses the possible parameter space of galaxies, the evolution on the manifold is considered. We find that constant and exponentially decreasing star formation histories form almost orthogonal modes of evolution on the manifold. Through these simple models, we understand that the two modes are closely related to gas content, which suggests the close relationship of the manifold to gas accretion. Without assuming a star formation history, a gas-regulated model reproduces an exponentially declining star formation history with a timescale of $sim$1.2 Gyrs on the manifold. Lastly, the found manifold suggests a paradigm where galaxies are characterized by their mass/scale and specific SFR, which agrees with previous studies of dimensionality reduction. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2210.05862v1

Galaxy-halo size relation from SDSS DR7 and the ELUCID simulation by Youcai Zhang et al. on Tuesday 11 October Based on galaxies in the Sloan Digital Sky Survey Data Release 7 (SDSS DR7) and dark matter haloes in the dark matter only, cosmological and constrained ELUCID simulation, we investigate the relation between the observed radii of central galaxies with stellar mass $gtrsim 10^{8} h^{-2}{rm M}_odot$ and the virial radii of their host dark matter haloes with virial mass $gtrsim 10^{10.5} h^{-1}{rm M}_odot$, and the dependence of galaxy-halo size relation on the halo spin and concentration. Galaxies in observation are matched to dark matter (sub-)haloes in the ELUCID simulation using a novel neighborhood subhalo abundance matching method. For galaxy 2D half-light radii $R_{50}$, we find that early- and late-type galaxies have the same power-law index 0.55 with $R_{50} propto R_{rm vir}^{0.55}$, although early-type galaxies have smaller 2D half-light radii than late-type galaxies at fixed halo virial radii. When converting the 2D half-light radii $R_{50}$ to 3D half-mass radii $r_{1/2}$, both early- and late-type galaxies display similar galaxy-halo size relations with $log r_{1/2} = 0.55 log (R_{rm vir}/210 h^{-1}{rm kpc}) + 0.39$. We find that the galaxy-halo size ratio $r_{1/2}/ R_{rm vir}$ decreases with increasing halo mass. At fixed halo mass, there is no significant dependence of galaxy-halo size ratio on the halo spin or concentration. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2210.05215v1

Accretion and Host-Galaxy Properties of 14 New "Changing-Look'' Active Galactic Nuclei Identified from the SDSS-V Survey by J. Wang et al. on Monday 10 October The widely accepted active galactic nucleus (AGN) paradigm has been recently challenged by the discovery of the so-called ``changing-look'' (CL) phenomenon characterized by spectral-type transitions. By comparing the SDSS-V and SDSS DR16 spectroscopic datasets, here we report the identification of 14 new CL-AGNs (redshift $z

The SDSS-Gaia View of the Color-Magnitude Relation for Blue Horizontal-Branch Stars by Fabrícia O. Barbosa et al. on Monday 10 October We present an updated sample of blue horizontal-branch (BHB) stars selected from the photometric and spectroscopic data from Sloan Digital Sky Survey and its associated project Sloan Extension for Galactic Understanding and Exploration (SEGUE). With this data, we selected candidates for A-type stars in the color-color space and then a mixture modeling technique was implemented in order to distinguish between BHB and main-sequence/blue-straggler stars based on their surface gravity values ($log rm{g}$) estimated by the SEGUE Stellar Parameter Pipeline. Our robust approach allows us to attribute individual probabilities of each star truly being in the BHB stage. Hence, our method is advantageous in comparison to previous SEGUE BHB selections that adopted simple $log rm{g}$ cuts. We also revisit the color-magnitude relation for these stars and propose two calibrations, based on updated distances for Galactic globular clusters, to estimate absolute magnitudes with $(g-r)_0$ and $(u-r)_0$ colors. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2210.02820v2

Machine learning technique for morphological classification of galaxies from the SDSS III Image-based inference of detailed features by V. Khramtsov et al. on Monday 26 September This paper follows series of our works on the applicability of various machine learning methods to the morphological galaxy classification (Vavilova et al., 2021, 2022). We exploited the sample of 315776 SDSS DR9 galaxies with absolute stellar magnitudes of -24m

High Mass Flow Rate in a BAL Outflow of Quasar SDSS J1130+0411 by Andrew Walker et al. on Wednesday 21 September We present the analysis of the absorption troughs of six outflows observed in quasar SDSS J1130+0411 ($z approx 3.98$) with radial velocities ranging from $-2400$ to $-15,400$ km s$^{-1}$. These spectra were taken with the Very Large Telescope/Ultraviolet and Visual Echelle Spectrograph over the rest frame wavelength range of $1135-1890$ r{A}. In the main outflow system ($v approx -3200$ km s$^{-1}$), we identify Fe II and several Fe II* absorption troughs as well as Si II and Si II* troughs, which we use to determine the electron number density $log n_e = 2.6_{-0.7}^{+0.8}$ cm$^{-3}$. Using the column densities of these and other ions, we determine a photoionization solution with hydrogen column density $log N_H = 21.44_{-0.33}^{+0.24}$ cm$^{-2}$ and ionization parameter $log U_H = -1.75_{-0.45}^{+0.28}$. From these values we derive the distance $R = 16_{-11}^{+23}$ kpc, the average mass flow rate $dot{M} = 4100_{-2400}^{+6600}$ $M_{odot}$ yr$^{-1}$, and the kinetic luminosity $log dot{E}_k = 46.13_{-0.37}^{+0.41}$ erg s$^{-1}$. This $dot{E}_k$ is $1.4_{-0.8}^{+2.2}$% of the quasar's Eddington luminosity, and therefore contributes significantly to AGN feedback. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2208.09990v2

Evidence of Galaxy Assembly Bias in SDSS DR7 Galaxy Samples from Count Statistics by Kuan Wang et al. on Wednesday 21 September We present observational constraints on the galaxy-halo connection, focusing particularly on galaxy assembly bias, from a novel combination of counts-in-cylinders statistics, $P(N_{rm{CIC}})$, with the standard measurements of the projected two-point correlation function, $w_{rm{p}}(r_{rm{p}})$, and number density, $n_{rm{gal}}$, of galaxies. We measure $n_{rm{gal}}$, $w_{rm{p}}(r_{rm{p}})$ and $P(N_{rm{CIC}})$ for volume-limited, luminosity-threshold samples of galaxies selected from SDSS DR7, and use them to constrain halo occupation distribution (HOD) models, including a model in which galaxy occupation depends upon a secondary halo property, namely halo concentration. We detect significant positive central assembly bias for the $M_r

Stellar Populations in type Ia supernova host galaxies at intermediate-high redshift: Star formation and metallicity enrichment histories by I. Millan-Irigoyen et al. on Wednesday 21 September We present a summary of our project that studies galaxies hosting type Ia supernova (SN Ia) at different redshifts. We present Gran Telescopio de Canarias (GTC) optical spectroscopy of six SN Ia host galaxies at redshift $zsim 0.4-0.5$. They are joined to a set of SN Ia host galaxies at intermediate-high redshift, which include galaxies from surveys SDSS and COSMOS. The final sample, after a selection of galaxy spectra in terms of signal-to-noise and other characteristics, consists of 680 galaxies with redshift in the range $0.04 < z < 1$. We perform an inverse stellar population synthesis with the code {sc fado} to estimate the star formation and enrichment histories of this set of galaxies, simultaneously obtaining their mean stellar age and metallicity and stellar mass. After analysing the correlations among these characteristics, we look for possible dependencies of the Hubble diagram residuals and supernova features (luminosity, color and strength parameter) on these stellar parameters. We find that the Hubble residuals show a clear dependence on the stellar metallicity weighted by mass with a slope of -0.061,mag,dex$^{-1}$, when represented in logarithmic scale, $log{ langle Z_{M}/Z_{odot}rangle }$. This result supports our previous findings obtained from gas oxygen abundances for local and SDSS-survey galaxies. Comparing with other works from the literature that also use the stellar metallicity, we find a similar value, but with more precision and a better significance (2.08 vs $sim$ 1.1), due to the higher number of objects and wider range of redshift of our sample. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2209.10242v1

Conditional HI mass functions and the HI-to-halo mass relation in the local Universe by Xiao Li et al. on Sunday 18 September We present a new HI mass estimator which relates the HI-to-stellar mass ratio to four galaxy properties: stellar surface mass density, color index $u-r$, stellar mass and concentration index, with the scatter of individual galaxies around the mean HI mass modeled with a Gaussian distribution. We calibrate the estimator using the xGASS sample, including both HI detection and non-detection, and constrain the model parameters through Bayesian inferences. Tests with mock catalogs demonstrate that our estimator provides unbiased HI masses for optical samples like the SDSS, thus suitable for statistical studies of HI gas contents in galaxies and dark matter halos. We apply our estimator to the SDSS spectroscopic sample to estimate the local HI mass function (HIMF), the conditional HI mass function (CHIMF) in galaxy groups and the HI-halo mass (HIHM) relation. Our HIMF agrees with the ALFALFA measurements at $M_{HI}gtrsim 5times 10^9M_{odot}$, but with higher amplitude and a steeper slope at lower masses. We show that this discrepancy is caused primarily by the cosmic variance which is corrected for the SDSS sample but not for the ALFALFA. The CHIMFs for all halo masses can be described by a single Schechter function, and this is true for red, blue and satellite galaxies. For central galaxies the CHIMFs show a double-Gaussian profile, with the two components contributed by the red and blue galaxies, respectively. The total HI mass in a group increases monotonically with halo mass. The HI mass of central galaxies in galaxy groups increases rapidly with halo mass only at $M_hlesssim10^{12}M_{odot}$, while the mass dependence becomes much weaker at higher halo masses. The observed HI-halo mass relation is not reproduced by current hydrodynamic simulations and semi-analytic models of galaxy formation. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2209.07691v1

뉴스룸! S7E08 백신 관련 가짜뉴스, 아프가니스탄 과학계의 위기, 암흑에너지의 존재를 밝힌 3D 우주지도 최 팀장 : 코로나19 가짜뉴스가 퍼지는 경로, 백신을 불안해하는 사람을 어떻게 설득할 수 있을까? 이용 : SNS가 공공재가 되면서 불거지는 가짜 뉴스 문제와 모호한 검열 기준 곽재식 : 아프가니스탄 과학계의 위기, 스템(STEM) 패러독스 K 박사 : 암흑 에너지는 존재한다! 20년간 3D 우주지도를 그린 슬론 디지털 스카이 서베이(Sloan Digital Sky Survey, SDSS) 과학과 사람들 제공

A mini-epsidoe with (fellow data science podcaster) Stephanie Hicks. Stephanie highlights the keynote speakers at SDSS 2020 along with the conference themes. Stephanie will be returning in a few weeks to discuss her own research at the nexus of data science, genomics, and public health.

Dave Hunter highlight a variety of cool life science collaborations he has worked on, including the network models used to describe AIDS transmissions and mixture modelling to describe pediatric cognitive tests. We then talk about the upcoming SDSS 2020 conference, and its newest additions to benefit early career researchers.