Radio telescope network located mainly in the Netherlands
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Sponsored by the Great Contagion, so deadly the god in charge of reporting on it died by proxy Welcome to our new game of Exalted (in Fellowship)! We had some IRL friends wanting to get into TTRPGs, so we hosted them a game of Fellowship set in the Exalted universe. The players are new to the hobby, the game and the setting. The pitch for the game is that it's a full circle Lunar campaign set at the late Shogunate era / onset of the Balorian Crusade. The tone is goofy gonzo, and we play fast and loose with the setting, wrecking things as we go. Initially the players wanted to play something with mechas / warstriders, but we ditched that idea without scaling down the threats they are facing, since hey, it's Fellowship, it's rather forgiving for that ;). Our cast for this series includes: - Peter as the Overlord Framework, Prince Balor of the Dreadful Gaze - Vanessa as Anastasia Volkova, a No Moon Lunar, the Collector Playbook - Galaxy as Lofar the Greedy, a Full Moon Lunar, the Dwarf Playbook - Jeff as Siegfried, a Full Moon Lunar, the Elf Playbook - Scott as Cat of the Endless Void, Puddle of Unknown Liquid, a Changing Moon Lunar, the Rain Playbook
Onder leiding van Leidse sterrenkundigen is het een internationaal team van onderzoekers gelukt om met een nieuwe kalibratietechniek de verstoringen van de aardatmosfeer te omzeilen. Daarmee wordt het mogelijk om bijvoorbeeld uitbarstende zwarte gaten beter te bestuderen. Met de nieuwe techniek lukte het ze namelijk om scherpe radiokaarten op lage frequenties te maken. Dit werd altijd gezien als onmogelijk, omdat deze frequenties worden verstoord door de ionosfeer op zo'n 80 kilometer boven de aarde. Dit hebben de onderzoekers nu dus weten te omzeilen. Met de nieuwe methode brachten ze al plasma's van oude uitbarstingen van zwarte gaten in beeld. Mogelijk is de techniek ook geschikt om exoplaneten te vinden die om kleine sterren draaien. Voor het onderzoek werd de LOFAR-telescoop in Drenthe gebruikt, op dit moment één van de beste radiotelescopen ter wereld voor lage frequenties. Meer data worden op het moment nog geanalyseerd. Uiteindelijk hopen ze de hele noordelijke hemel in kaart te kunnen brengen op deze lage frequenties. Lees hier meer over het onderzoek: Radio-astronomen omzeilen storende aardatmosfeer met nieuwe kalibratietechniekSee omnystudio.com/listener for privacy information.
Czym są galaktyki i ich środowiska międzygwiazdowe? Czego dowiadujemy się z analizy środowiska międzygwiazdowego? W kolejnym odcinku podcastu "Wszechświat" dr Karolina Mania i dr hab. (prof. UJ) Marian Soida (dyrektor Instytutu Obserwatorium Astronomicznego UJ) rozmawiają o galaktykach i roli pola magnetycznego w tzw. środowisku międzygwiazdowym. Z odcinka dowiecie się jak badamy galaktyki, czym jest synteza miary rotacji i w czym pomocny jest LOFAR (ang. LOw Frequency ARray). Gość: dr hab. Marian Soida, prof. UJ, dyrektor Instytutu Obserwatorium Astronomicznego UJ, prowadzący badania nad polem magnetycznym w środowisku międzygwiazdowym. Prowadzący: adw. dr Karolina Mania, adiunkt w Katedrze Zarządzania Strategicznego w Wydziale Zarządzania i Komunikacji Społecznej UJ Dofinansowano ze środków Ministerstwa Edukacji i Nauki z programu Społeczna Odpowiedzialność Nauki w ramach projektu „Nauka na żywo: wszechświat, życie, umysł". Kwota dofinansowania 540 200,00 zł, całkowita wartość zadania 600 200 zł.
Investigadores confirmaron que los satélites Starlink de SpaceX están "filtrando" ondas de radio de baja frecuencia, lo que podría afectar nuestra capacidad para realizar astronomía. Utilizando el telescopio LOFAR, observaron radiaciones electromagnéticas no intencionadas emitidas por los satélites de SpaceX. Este fenómeno podría interrumpir la investigación astronómica y, aunque la afectación es pequeña, puede aumentar con la constante adición de nuevos satélites.A medida que la órbita terrestre se llena, los efectos de los satélites en nuestra exploración espacial se vuelven cada vez más preocupantes.A medida que el cielo sobre la Tierra se llena de satélites, la preocupación aumenta. Actualmente, se estima que SpaceX tiene 4,365 de sus pequeños satélites de internet en la órbita terrestre, y planea lanzar miles más. Con este nivel de saturación, se observaron 68 satélites pertenecientes a la constelación Starlink y se detectó una fuga electromagnética.Los investigadores pensaban que los satélites podrían estar emitiendo ondas de radio no intencionadas fuera de la banda de comunicación habitual. Esta emisión parece ser involuntaria y proviene de la electrónica de los satélites. El problema es que en el espacio, las normas de control de interferencias electromagnéticas no aplican.Sin embargo, ya se está trabajando en una solución. Los investigadores han contactado a SpaceX, que está buscando formas de reducir o eliminar esta fuga involuntaria. Aunque hay miles de máquinas en el espacio, apenas estamos en el comienzo de la tecnología de constelación de satélites, por lo que este problema ha sido detectado relativamente temprano.Fuentes:ScienceAlert: Los satélites Starlink de SpaceX están filtrando radiación, confirman los científicosSciTechDaily: LOFAR descubre el secreto de Starlink: Emisiones electromagnéticas no intencionadas de los satélites de SpaceXImagen WikimediaEncuentra también nuestro pódcast más largo y completo en El Siglo 21 es HoyThis show is part of the Spreaker Prime Network, if you are interested in advertising on this podcast, contact us at https://www.spreaker.com/show/5835407/advertisement
Interferometric imaging of the type IIIb and U radio bursts observed with LOFAR on 22 August 2017 by Bartosz Dabrowski et al. on Thursday 24 November The Sun is the source of different types of radio bursts that are associated with solar flares, for example. Among the most frequently observed phenomena are type III solar bursts. Their radio images at low frequencies (below 100 MHz) are relatively poorly studied due to the limitations of legacy radio telescopes. We study the general characteristics of types IIIb and U with stria structure solar radio bursts in the frequency range of 20 - 80 MHz, in particular the source size and evolution in different altitudes, as well as the velocity and energy of electron beams responsible for their generation. In this work types IIIb and U with stria structure radio bursts are analyzed using data from the LOFAR telescope including dynamic spectra and imaging observations, as well as data taken in the X-ray range (GOES and RHESSI satellites) and in the extreme ultraviolet (SDO satellite). In this study we determined the source size limited by the actual shape of the contour at particular frequencies of type IIIb and U solar bursts in a relatively wide frequency band from 20 to 80 MHz. Two of the bursts seem to appear at roughly the same place in the studied active region and their source sizes are similar. It is different in the case of another burst, which seems to be related to another part of the magnetic field structure in this active region. The velocities of the electron beams responsible for the generation of the three bursts studied here were also found to be different. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.12756v1
Interferometric imaging of the type IIIb and U radio bursts observed with LOFAR on 22 August 2017 by Bartosz Dabrowski et al. on Wednesday 23 November The Sun is the source of different types of radio bursts that are associated with solar flares, for example. Among the most frequently observed phenomena are type III solar bursts. Their radio images at low frequencies (below 100 MHz) are relatively poorly studied due to the limitations of legacy radio telescopes. We study the general characteristics of types IIIb and U with stria structure solar radio bursts in the frequency range of 20 - 80 MHz, in particular the source size and evolution in different altitudes, as well as the velocity and energy of electron beams responsible for their generation. In this work types IIIb and U with stria structure radio bursts are analyzed using data from the LOFAR telescope including dynamic spectra and imaging observations, as well as data taken in the X-ray range (GOES and RHESSI satellites) and in the extreme ultraviolet (SDO satellite). In this study we determined the source size limited by the actual shape of the contour at particular frequencies of type IIIb and U solar bursts in a relatively wide frequency band from 20 to 80 MHz. Two of the bursts seem to appear at roughly the same place in the studied active region and their source sizes are similar. It is different in the case of another burst, which seems to be related to another part of the magnetic field structure in this active region. The velocities of the electron beams responsible for the generation of the three bursts studied here were also found to be different. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.12756v1
The LOFAR Tied-Array All-Sky Survey: Timing of 35 radio pulsars and an overview of the properties of the LOFAR pulsar discoveries by E. van der Wateren et al. on Tuesday 22 November The LOFAR Tied-Array All-Sky Survey (LOTAAS) is the most sensitive untargeted radio pulsar survey performed at low radio frequencies (119--151,MHz) to date and has discovered 76 new radio pulsars, among which the 23.5-s pulsar J0250+5854, up until recently the slowest-spinning radio pulsar known. Here, we report on the timing solutions of 35 pulsars discovered by LOTAAS, which include a nulling pulsar and a mildly recycled pulsar, and thereby complete the full timing analysis of the LOTAAS pulsar discoveries. We give an overview of the findings from the full LOTAAS sample of 76 pulsars, discussing their pulse profiles, radio spectra and timing parameters. We found that the pulse profiles of some of the pulsars show profile variations in time or frequency and while some pulsars show signs of scattering, a large majority display no pulse broadening. The LOTAAS discoveries have on average steeper radio spectra and have longer spin periods ($1.4times$) as well as lower spin-down rates ($3.1times$) compared to the known pulsar population. We discuss the cause of these differences, and attribute them to a combination of selection effects of the LOTAAS survey as well as previous pulsar surveys, though can not rule out that older pulsars tend to have steeper radio spectra. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.11080v1
3D Detection and Characterisation of ALMA Sources through Deep Learning by Michele Delli Veneri et al. on Tuesday 22 November We present a Deep-Learning (DL) pipeline developed for the detection and characterization of astronomical sources within simulated Atacama Large Millimeter/submillimeter Array (ALMA) data cubes. The pipeline is composed of six DL models: a Convolutional Autoencoder for source detection within the spatial domain of the integrated data cubes, a Recurrent Neural Network (RNN) for denoising and peak detection within the frequency domain, and four Residual Neural Networks (ResNets) for source characterization. The combination of spatial and frequency information improves completeness while decreasing spurious signal detection. To train and test the pipeline, we developed a simulation algorithm able to generate realistic ALMA observations, i.e. both sky model and dirty cubes. The algorithm simulates always a central source surrounded by fainter ones scattered within the cube. Some sources were spatially superimposed in order to test the pipeline deblending capabilities. The detection performances of the pipeline were compared to those of other methods and significant improvements in performances were achieved. Source morphologies are detected with subpixel accuracies obtaining mean residual errors of $10^{-3}$ pixel ($0.1$ mas) and $10^{-1}$ mJy/beam on positions and flux estimations, respectively. Projection angles and flux densities are also recovered within $10%$ of the true values for $80%$ and $73%$ of all sources in the test set, respectively. While our pipeline is fine-tuned for ALMA data, the technique is applicable to other interferometric observatories, as SKA, LOFAR, VLBI, and VLTI. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.11462v1
Exploring Earth's Ionosphere and its effect on low radio frequency observation with the uGMRT and the SKA by Sarvesh Mangla et al. on Monday 21 November The Earth's ionosphere introduces systematic effects that limit the performance of a radio interferometer at low frequencies ($lesssim 1$,GHz). These effects become more pronounced for severe geomagnetic activities or observations involving longer baselines of the interferometer. The uGMRT, a pathfinder for the Square Kilometre Array (SKA), is located in between the northern crest of the Equatorial Ionisation Anomaly (EIA) and the magnetic equator. Hence, this telescope is more prone to severe ionospheric conditions and is a unique radio interferometer for studying the ionosphere. Here, we present 235,MHz observations with the GMRT, showing significant ionospheric activities over a solar minimum. In this work, we have characterised the ionospheric disturbances observed with the GMRT and compared them with ionospheric studies and observations with other telescopes like the VLA, MWA and LOFAR situated at different magnetic latitudes. We have estimated the ionospheric total electron content (TEC) gradient over the full GMRT array which shows an order of magnitude higher sensitivity compared to the Global Navigation Satellite System (GNSS). Furthermore, this article uses the ionospheric characteristics estimated from the observations with uGMRT, VLA, LOFAR and MWA to forecast the effects on the low-frequency observations with the SKA1-MID and SKA1-LOW in future. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.09738v1
The LOFAR Tied-Array All-Sky Survey: Timing of 35 radio pulsars and an overview of the properties of the LOFAR pulsar discoveries by E. van der Wateren et al. on Monday 21 November The LOFAR Tied-Array All-Sky Survey (LOTAAS) is the most sensitive untargeted radio pulsar survey performed at low radio frequencies (119--151,MHz) to date and has discovered 76 new radio pulsars, among which the 23.5-s pulsar J0250+5854, up until recently the slowest-spinning radio pulsar known. Here, we report on the timing solutions of 35 pulsars discovered by LOTAAS, which include a nulling pulsar and a mildly recycled pulsar, and thereby complete the full timing analysis of the LOTAAS pulsar discoveries. We give an overview of the findings from the full LOTAAS sample of 76 pulsars, discussing their pulse profiles, radio spectra and timing parameters. We found that the pulse profiles of some of the pulsars show profile variations in time or frequency and while some pulsars show signs of scattering, a large majority display no pulse broadening. The LOTAAS discoveries have on average steeper radio spectra and have longer spin periods ($1.4times$) as well as lower spin-down rates ($3.1times$) compared to the known pulsar population. We discuss the cause of these differences, and attribute them to a combination of selection effects of the LOTAAS survey as well as previous pulsar surveys, though can not rule out that older pulsars tend to have steeper radio spectra. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.11080v1
Exploring Earth's Ionosphere and its effect on low radio frequency observation with the uGMRT and the SKA by Sarvesh Mangla et al. on Monday 21 November The Earth's ionosphere introduces systematic effects that limit the performance of a radio interferometer at low frequencies ($lesssim 1$,GHz). These effects become more pronounced for severe geomagnetic activities or observations involving longer baselines of the interferometer. The uGMRT, a pathfinder for the Square Kilometre Array (SKA), is located in between the northern crest of the Equatorial Ionisation Anomaly (EIA) and the magnetic equator. Hence, this telescope is more prone to severe ionospheric conditions and is a unique radio interferometer for studying the ionosphere. Here, we present 235,MHz observations with the GMRT, showing significant ionospheric activities over a solar minimum. In this work, we have characterised the ionospheric disturbances observed with the GMRT and compared them with ionospheric studies and observations with other telescopes like the VLA, MWA and LOFAR situated at different magnetic latitudes. We have estimated the ionospheric total electron content (TEC) gradient over the full GMRT array which shows an order of magnitude higher sensitivity compared to the Global Navigation Satellite System (GNSS). Furthermore, this article uses the ionospheric characteristics estimated from the observations with uGMRT, VLA, LOFAR and MWA to forecast the effects on the low-frequency observations with the SKA1-MID and SKA1-LOW in future. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.09738v1
3D Detection and Characterisation of ALMA Sources through Deep Learning by Michele Delli Veneri et al. on Monday 21 November We present a Deep-Learning (DL) pipeline developed for the detection and characterization of astronomical sources within simulated Atacama Large Millimeter/submillimeter Array (ALMA) data cubes. The pipeline is composed of six DL models: a Convolutional Autoencoder for source detection within the spatial domain of the integrated data cubes, a Recurrent Neural Network (RNN) for denoising and peak detection within the frequency domain, and four Residual Neural Networks (ResNets) for source characterization. The combination of spatial and frequency information improves completeness while decreasing spurious signal detection. To train and test the pipeline, we developed a simulation algorithm able to generate realistic ALMA observations, i.e. both sky model and dirty cubes. The algorithm simulates always a central source surrounded by fainter ones scattered within the cube. Some sources were spatially superimposed in order to test the pipeline deblending capabilities. The detection performances of the pipeline were compared to those of other methods and significant improvements in performances were achieved. Source morphologies are detected with subpixel accuracies obtaining mean residual errors of $10^{-3}$ pixel ($0.1$ mas) and $10^{-1}$ mJy/beam on positions and flux estimations, respectively. Projection angles and flux densities are also recovered within $10%$ of the true values for $80%$ and $73%$ of all sources in the test set, respectively. While our pipeline is fine-tuned for ALMA data, the technique is applicable to other interferometric observatories, as SKA, LOFAR, VLBI, and VLTI. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.11462v1
Abell 2255 est un amas contenant plusieurs milliers de galaxies situées à 200 mégaparsecs de la Terre. Des astrophysiciens néerlandais et italiens l'ont étudié dans le domaine radio avec le radiotélescope LOFAR et trouvent qu'il est rempli d'électrons relativistes et de champs magnétiques. Ils publient leur étude dans Science Advances. Soutenez Ca Se Passe Là-Haut en m'offrant un verre sur Coffee : https://www.coffee-france.fr/p/Z2JI5ZFVQUC1
The Planck clusters in the LOFAR sky III LoTSS-DR2: Dynamic states and density fluctuations of the intracluster medium by X. Zhang et al. on Sunday 16 October The footprint of LoTSS-DR2 covers 309 PSZ2 galaxy clusters, 83 of which host a radio halo and 26 host a radio relic(s). It provides us an excellent opportunity to statistically study the properties of extended cluster radio sources, especially their connection with merging activities. We aim to quantify cluster dynamic states to investigate their relation with the occurrence of extended radio sources. We also search for connections between intracluster medium (ICM) turbulence and nonthermal characteristics of radio halos in the LoTSS-DR2. We analyzed XMM-Newton and Chandra archival X-ray data and computed concentration parameters and centroid shifts that indicate the dynamic states of the clusters. We also performed a power spectral analysis of the X-ray surface brightness (SB) fluctuations to investigate large-scale density perturbations and estimate the turbulent velocity dispersion. The power spectral analysis results in a large scatter density fluctuation amplitude. We therefore only found a marginal anticorrelation between density fluctuations and cluster relaxation state, and we did not find a correlation between density fluctuations and radio halo power. Nevertheless, the injected power for particle acceleration calculated from turbulent dissipation is correlated with the radio halo power, where the best-fit unity slope supports the turbulent (re)acceleration scenario. Two different acceleration models, transit-time damping and adiabatic stochastic acceleration, cannot be distinguished due to the large scatter of the estimated turbulent Mach number. We introduced a new quantity $[kTcdot Y_X]_{r_mathrm{RH}}$, which is proportional to the turbulent acceleration power assuming a constant Mach number. This quantity is strongly correlated with radio halo power, where the slope is also unity. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2210.07284v1
Magnetic field evolution in cosmic filaments with LOFAR data by E. Carretti et al. on Thursday 13 October Measuring the magnetic field in cosmic filaments reveals how the Universe is magnetised and the process that magnetised it. Using the Rotation Measures (RM) at 144-MHz from the LoTSS DR2 data, we analyse the rms of the RM extragalactic component as a function of redshift to investigate the evolution with redshift of the magnetic field in filaments. From previous results, we find that the extragalactic term of the RM rms at 144-MHz is dominated by the contribution from filaments (more than 90 percent). Including an error term to account for the minor contribution local to the sources, we fit the data with a model of the physical filament magnetic field, evolving as $B_f = B_{f,0},(1+z)^alpha$ and with a density drawn from cosmological simulations of five magnetogenesis scenarios. We find that the best-fit slope is in the range $alpha = [-0.2, 0.1]$ with uncertainty of $sigma_alpha = 0.4$--0.5, which is consistent with no evolution. The comoving field decreases with redshift with a slope of $gamma = alpha - 2 = [-2.2, -1.9]$. The mean field strength at $z=0$ is in the range $B_{f,0}=39$--84~nG. For a typical filament gas overdensity of $delta_g=10$ the filament field strength at $z=0$ is in the range $B_{f,0}^{10}=8$--26~nG. A primordial stochastic magnetic field model with initial comoving field of $B_{rm Mpc} = 0.04$--0.11~nG is favoured. The primordial uniform field model is rejected. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2210.06220v1
Magnetic field evolution in cosmic filaments with LOFAR data by E. Carretti et al. on Thursday 13 October Measuring the magnetic field in cosmic filaments reveals how the Universe is magnetised and the process that magnetised it. Using the Rotation Measures (RM) at 144-MHz from the LoTSS DR2 data, we analyse the rms of the RM extragalactic component as a function of redshift to investigate the evolution with redshift of the magnetic field in filaments. From previous results, we find that the extragalactic term of the RM rms at 144-MHz is dominated by the contribution from filaments (more than 90 percent). Including an error term to account for the minor contribution local to the sources, we fit the data with a model of the physical filament magnetic field, evolving as $B_f = B_{f,0},(1+z)^alpha$ and with a density drawn from cosmological simulations of five magnetogenesis scenarios. We find that the best-fit slope is in the range $alpha = [-0.2, 0.1]$ with uncertainty of $sigma_alpha = 0.4$--0.5, which is consistent with no evolution. The comoving field decreases with redshift with a slope of $gamma = alpha - 2 = [-2.2, -1.9]$. The mean field strength at $z=0$ is in the range $B_{f,0}=39$--84~nG. For a typical filament gas overdensity of $delta_g=10$ the filament field strength at $z=0$ is in the range $B_{f,0}^{10}=8$--26~nG. A primordial stochastic magnetic field model with initial comoving field of $B_{rm Mpc} = 0.04$--0.11~nG is favoured. The primordial uniform field model is rejected. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2210.06220v1
Testing afterglow models of FRB 200428 with early post-burst observations of SGR 1935+2154 by A. J. Cooper et al. on Thursday 13 October We present LOFAR imaging observations from the April/May 2020 active episode of magnetar SGR 1935+2154. We place the earliest radio limits on persistent emission following the low-luminosity fast radio burst FRB 200428 from the magnetar. We also perform an image-plane search for transient emission and find no radio flares during our observations. We examine post-FRB radio upper limits in the literature and find that all are consistent with the multi-wavelength afterglow predicted by the synchrotron maser shock model interpretation of FRB 200428. However, early optical observations appear to rule out the simple versions of the afterglow model with constant-density circumburst media. We show that these constraints may be mitigated by adapting the model for a wind-like environment, but only for a limited parameter range. In addition, we suggest that late-time non-thermal particle acceleration occurs within the afterglow model when the shock is no longer relativistic, which may prove vital for detecting afterglows from other Galactic FRBs. We also discuss future observing strategies for verifying either magnetospheric or maser shock FRB models via rapid radio observations of Galactic magnetars and nearby FRBs. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2210.06547v1
Learning to detect RFI in radio astronomy without seeing it by Michael Mesarcik et al. on Tuesday 11 October Radio Frequency Interference (RFI) corrupts astronomical measurements, thus affecting the performance of radio telescopes. To address this problem, supervised segmentation models have been proposed as candidate solutions to RFI detection. However, the unavailability of large labelled datasets, due to the prohibitive cost of annotating, makes these solutions unusable. To solve these shortcomings, we focus on the inverse problem; training models on only uncontaminated emissions thereby learning to discriminate RFI from all known astronomical signals and system noise. We use Nearest-Latent-Neighbours (NLN) - an algorithm that utilises both the reconstructions and latent distances to the nearest-neighbours in the latent space of generative autoencoding models for novelty detection. The uncontaminated regions are selected using weak-labels in the form of RFI flags (generated by classical RFI flagging methods) available from most radio astronomical data archives at no additional cost. We evaluate performance on two independent datasets, one simulated from the HERA telescope and another consisting of real observations from LOFAR telescope. Additionally, we provide a small expert-labelled LOFAR dataset (i.e., strong labels) for evaluation of our and other methods. Performance is measured using AUROC, AUPRC and the maximum F1-score for a fixed threshold. For the simulated data we outperform the current state-of-the-art by approximately 1% in AUROC and 3% in AUPRC for the HERA dataset. Furthermore, our algorithm offers both a 4% increase in AUROC and AUPRC at a cost of a degradation in F1-score performance for the LOFAR dataset, without any manual labelling. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2207.00351v2
Magnetohydrodynamic simulation of coronal mass ejections using interplanetary scintillation data observed from radio sites ISEE and LOFAR by Kazumasa Iwai et al. on Monday 26 September Interplanetary scintillation (IPS) is a useful tool for detecting coronal mass ejections (CMEs) throughout interplanetary space. Global magnetohydrodynamic (MHD) simulations of the heliosphere, which are usually used to predict the arrival and geo-effectiveness of CMEs, can be improved using IPS data. In this study, we demonstrate an MHD simulation that includes IPS data from multiple stations to improve CME modelling. The CMEs, which occurred on 09-10 September 2017, were observed over the period 10-12 September 2017 using the Low-Frequency Array (LOFAR) and IPS array of the Institute for Space-Earth Environmental Research (ISEE), Nagoya University, as they tracked through the inner heliosphere. We simulated CME propagation using a global MHD simulation, SUSANOO-CME, in which CMEs were modeled as spheromaks, and the IPS data were synthesised from the simulation results. The MHD simulation suggests that the CMEs merged in interplanetary space, forming complicated IPS g-level distributions in the sky map. We found that the MHD simulation that best fits both LOFAR and ISEE data provided a better reconstruction of the CMEs and a better forecast of their arrival at Earth than from measurements when these simulations were fit from the ISEE site alone. More IPS data observed from multiple stations at different local times in this study can help reconstruct the global structure of the CME, thus improving and evaluating the CME modelling. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2209.12486v1
Assessing the impact of two independent direction-dependent calibration algorithms on the LOFAR 21-cm signal power spectrum by H. Gan et al. on Sunday 18 September Detecting the 21-cm signal from the Epoch of Reionisation (EoR) is challenging due to the strong astrophysical foregrounds, ionospheric effects, radio frequency interference and instrumental effects. Understanding and calibrating these effects are crucial for the detection. In this work, we introduce a newly developed direction-dependent (DD) calibration algorithm DDECAL and compare its performance with an existing algorithm, SAGECAL, in the context of the LOFAR-EoR 21-cm power spectrum experiment. In our data set, the North Celestial Pole (NCP) and its flanking fields were observed simultaneously. We analyse the NCP and one of its flanking fields. The NCP field is calibrated by the standard pipeline, using SAGECAL with an extensive sky model and 122 directions, and the flanking field is calibrated by DDECAL and SAGECAL with a simpler sky model and 22 directions. Additionally, two strategies are used for subtracting Cassiopeia A and Cygnus A. The results show that DDECAL performs better at subtracting sources in the primary beam region due to the application of a beam model, while SAGECAL performs better at subtracting Cassiopeia A and Cygnus A. This indicates that including a beam model during DD calibration significantly improves the performance. The benefit is obvious in the primary beam region. We also compare the 21-cm power spectra on two different fields. The results show that the flanking field produces better upper limits compared to the NCP in this particular observation. Despite the minor differences between DDECAL and SAGECAL due to the beam application, we find that the two algorithms yield comparable 21-cm power spectra on the LOFAR-EoR data after foreground removal. Hence, the current LOFAR-EoR 21-cm power spectrum limits are not likely to depend on the DD calibration method. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2209.07854v1
Deep low-frequency radio observations of Abell 2256 II: The ultra-steep spectrum radio halo by K. Rajpurohit et al. on Thursday 08 September We present the first detailed analysis of the radio halo in the merging galaxy cluster Abell 2256 using the LOFAR, uGMRT, and VLA. These observations combined with archival X-ray data allowed us to study the halo emission with unprecedented detail. The integrated radio emission from the entire halo is characterized by an ultra-steep spectrum, which can be described by a power law with $alpha_{144 rm MHz}^{1.5 rm GHz}=-1.63pm0.03$, and a radial steepening in the outer regions. The halo is significantly underluminous according to the scaling relations between radio power and mass at 1.4 GHz but not at 150 MHz; ultra-steep spectrum halos are predicted statistically underluminous. Despite the complex structure of this system, the radio halo morphology is remarkably similar to that of the X-ray emission. The radio surface brightness distribution across the halo is strongly correlated with the X-ray brightness of the intracluster medium. The derived correlations show sublinear slopes and there are distinct structures: the core is $rm I_{R}propto I_{X}^{1.51}$, the outermost region $rm I_{R}propto I_{X}^{0.41}$, and we find radio morphological connections with X-ray discontinuities. We also find a strong anti-correlation between the radio spectral index and the X-ray surface brightness, implying radial steepening. We suggests that the halo core is either related to old plasma from previous AGN activity, being advected, compressed and re-accelerated by mechanisms activated by the cold front or the turbulence is less strong and magnetic field is strong in the core. The change in the radio vs X-ray correlation slopes in the outer regions of the halo could be due to a radial decline of magnetic field, increase in the number density of seed particles or increasing turbulence. Our findings suggest that that the emitting volume is not homogenous according to turbulence re-acceleration models. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2209.03288v1
Deep low-frequency radio observations of Abell 2256 II: The ultra-steep spectrum radio halo by K. Rajpurohit et al. on Thursday 08 September We present the first detailed analysis of the radio halo in the merging galaxy cluster Abell 2256 using the LOFAR, uGMRT, and VLA. These observations combined with archival X-ray data allowed us to study the halo emission with unprecedented detail. The integrated radio emission from the entire halo is characterized by an ultra-steep spectrum, which can be described by a power law with $alpha_{144 rm MHz}^{1.5 rm GHz}=-1.63pm0.03$, and a radial steepening in the outer regions. The halo is significantly underluminous according to the scaling relations between radio power and mass at 1.4 GHz but not at 150 MHz; ultra-steep spectrum halos are predicted statistically underluminous. Despite the complex structure of this system, the radio halo morphology is remarkably similar to that of the X-ray emission. The radio surface brightness distribution across the halo is strongly correlated with the X-ray brightness of the intracluster medium. The derived correlations show sublinear slopes and there are distinct structures: the core is $rm I_{R}propto I_{X}^{1.51}$, the outermost region $rm I_{R}propto I_{X}^{0.41}$, and we find radio morphological connections with X-ray discontinuities. We also find a strong anti-correlation between the radio spectral index and the X-ray surface brightness, implying radial steepening. We suggests that the halo core is either related to old plasma from previous AGN activity, being advected, compressed and re-accelerated by mechanisms activated by the cold front or the turbulence is less strong and magnetic field is strong in the core. The change in the radio vs X-ray correlation slopes in the outer regions of the halo could be due to a radial decline of magnetic field, increase in the number density of seed particles or increasing turbulence. Our findings suggest that that the emitting volume is not homogenous according to turbulence re-acceleration models. arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2209.03288v1
Astronomers have developed many ways to find planets in other star systems. The latest is with radio waves. The first planet found that way was detected a couple of years ago by LOFAR, an array of radio telescopes in Europe. The planet orbits Gliese 1151, a star that's 26 light-years away. The star is only a fraction the size and mass of the Sun, and its surface is thousands of degrees cooler than the Sun's. LOFAR picked up hints that something small was orbiting close to the star, but there was a wide range on the numbers. An instrument in the Canary Islands narrowed it down a bit. And another instrument zeroed in even more. The Habitable-zone Planet Finder is attached to the Hobby-Eberly Telescope at McDonald Observatory. It's designed to find planets orbiting small, faint stars. Its observations revealed that the planet at Gliese 1151 is about two and a half times the mass of Earth. It orbits the star once every couple of days. It's inside the star's corona — a thin but hot outer atmosphere of charged particles. The planet interacts with the corona in a way that creates radio waves. The discovery suggests that bigger radio telescopes in the future may be able to find many more planets — adding to the catalog of worlds beyond the solar system. Gliese 1151 is in Ursa Major. As night falls, the star's close to the lower left of the bowl of the Big Dipper. But it's too faint to see without a telescope. Script by Damond Benningfield Support McDonald Observatory
Odcinek poświęcony tematyce radioteleskopów, a także rozproszonemu radioteleskopowi LOFAR, którego stacje znajdują się na terenie Polski.Niezależnie czy interesują Was pulsary, elektronika, radioastronomia czy krótkofalarstwo w odcinku znajdziecie coś dla siebie.Temat na forum: https://www.elektroda.pl/rtvforum/topic3911674.html
Bentornati!Oggi parliamo dell'astronomia nelle onde radio, un'astronomia che ha permesso di vedere e scoprire radiazioni nuove e sconosciute nell'Universo, come il nostro centro Galattico.Parliamo della storia dalle prime osservazioni, agli attuali radiotelescopi, come questi funzionano dando un piccolo sguardo al futuro e cosa ci aspetta.Vi metto i link di media Inaf su Lofar:- https://www.media.inaf.it/2022/02/25/mappa-lofar-milioni-sorgenti/ - https://www.media.inaf.it/2020/06/25/lo-splendido-caos-di-abell-2255/ Per seguirci sui nostri social :-Facebook: https://www.facebook.com/planetariodimodena-Instagram: https://www.instagram.com/planetariomodena/-Twitter: https://twitter.com/planetario_mo-Sito : https://www.planetariodimodena.it/Music Fanfare for Space by Kevin MacLeodLink: https://incompetech.filmmusic.io/song/3736-fanfare-for-spaceLicense: https://filmmusic.io/standard-license
Memorias: http://bit.ly/deo-memorias Noticias: La falta de materia oscura y las galaxias enanas. El misterio detrás de los rayos, revelado por LOFAR. Ingeniería de detalle para enviar con luz una sonda a Proxima. Cometa con órbita hiperbólica, con extrañas características. Volvimos a detectar a “Tatooine”, ahora desde la Tierra. Un nuevo tipo de estrella puede estar asociado a una fusión de enanas blancas Realizan: Adriana Araujo (U. Sergio Arboleda), German Chaparro, Juan C. Muñoz, Esteban Silva, Pablo Cuartas, Jorge I. Zuluaga (Instituto de Física de la Universidad de Antioquia). Dirige: Jorge I. Zuluaga, Profesor Titular del Pregrado de Astronomía, U. de A. Produce y Edita: Jhossua Giraldo, Pregrado de Astronomía U. de A.
Ein internationales Team von Astronomen hat mit Hilfe des LOFAR-Radioteleskops (Low Frequency Array) die größte und schärfste Karte des Himmels bei extrem niedrigen Radiofrequenzen erstellt. Es mag wie ein ganz normales Bild des Nachthimmels aussehen, aber was wir hier wirklich sehen, ist viel mehr als nur glitzernde Sterne. Jeder dieser weißen Punkte ist ein aktives supermassereiches schwarzes Loch. Quellen: https://www.astron.nl/a-starry-sky-made-of-more-than-25000-supermassive-black-holes/ https://arxiv.org/abs/2102.09238 https://www.astron.nl/telescopes/lofar/ Abonniere jetzt die Entropy, um keine der coolen & interessanten Episoden zu verpassen! Das unterstützt mich natürlich und hilft mir meinen Content zu verbessern und zu erweitern! Hier abonnieren: https://www.youtube.com/channel/UC5dBZm6ztKizdUnN7Puz3QQ?sub_confirmation=1 ♦ PATREON: https://www.patreon.com/entropy_wse ♦ TWITTER: https://twitter.com/Entropy_channel ♦ INSTAGRAM: https://www.instagram.com/roma_perezogin/ ♦ INSTAGRAM: https://www.instagram.com/entropy_channel/
Astronomers believe that nearly every galaxy has a supermassive black hole at its centre, this being true for our very own Milky Way. These objects exert such strong gravitational forces on the matter contained within them that it cannot escape the black hole's pull. Scientists using the LOFAR telescope in the Netherlands have been studying the impact that such black holes have on the Universe on a mind-bogglingly large scale. One of the scientists working on the project, Marisa Brienza from the University of Bologna, told Cameron Voisey what they found. Like this podcast? Please help us by supporting the Naked Scientists
Heute mit: Treibhausgase, Cybercrime, Kotlin, LOFAR
We sit down with Aine Flood, the Education and Public Engagement Manger with I-LOFAR radio telescope in Birr, County Offaly. She touches on who's best at talking science, misconceptions of science, and all things astronomy.
Una collaborazione internazionale ha individuato per la prima volta una nana bruna fredda grazie alle osservazioni di tre radiotelescopi
In this episode I chat to UCD PhD researcher Sean Mooney about life in astrophysics and his research into plasma jets that are released from black holes in distant galaxies using the LOFAR radiotelescope. We also chat about life as a PhD student, stand up comedy and why hes probably not cut out to be an astronaut. Follow me: MeganHanlon4
Er hangt een ster vlakbij onze aarde. Het is een gigantische kernreactor die onophoudelijk enorme hoeveelheden energie de ruimte in blaast. Onze zon, het lichtpunt in onze wereld. Hij staat altijd op een afstand zo'n 150 miljoen kilometer van ons af. Om dichterbij te kijken moeten we gebruik maken van high-tech telescopen. En dat is nodig ook: de zon kan namelijk gevaarlijk zijn. Zonnestormen lanceren allerlei deeltjes de ruimte in, die onze technologie in de war kunnen schoppen, denk aan luchtvaartproblemen, netwerkstoringen en enorme stroomuitval. Om deze zonnestormen beter te voorspellen werkt astronoom Michiel Brentjens van Instituut Astron mee aan een ware zonnetelescoop. En hij werkt met de grootste radiotelescoop ter wereld: Lofar. Hij praat met ons over de laatste ontwikkelingen in het onderzoek naar de zon.
Our featured guest for this special 100th episode is Dr Vanessa Moss, astronomer and Head of CSIRO’s ASKAP Science Operations. CSIRO is Australia’s leading science organisation and ASKAP is the Australian Square Kilometre Array Pathfinder radio telescope array in Western Australia. Vanessa tells us about her PhD ‘The Galactic ecosystem: Outflow and infall in the halo of the Milky Way” and her work at Sydney Observatory. We hear about her move over to Dwingeloo in the Netherlands to work as a telescope scientist with ASTRON, working with the Apertif upgrade on the WSRT and LOFAR, We look at the Big Data issues growing in radio astronomy and her vision to harness VR as a way of visualising both data, workflow and instrument training. We hear about her current Milky Way Halo research, the SEAFOG project and working on the FLASH team.
The 365 Days of Astronomy, the daily podcast of the International Year of Astronomy 2009
The first episode of the Urban Astronomer Podcast's second season is an Interview with Dr. Wendy Williams. Wendy is a radio astronomer from Cape Town, currently working for the University of Leiden on the LOFAR array. She talks about her work, and how the telescope she works with creates an image from radio signals. Brief bio of the podcaster: Allen is an amateur astronomer, an IT professional, a podcaster, a father of five beautiful kids and a barely competent chess player. He is also the director of the Citizen Science Section of the Astronomical Society of South Africa, where he promotes the uptake of Citizen Science among South African amateur astronomers. We've added a new way to donate to 365 Days of Astronomy to support editing, hosting, and production costs. Just visit: https://www.patreon.com/365DaysOfAstronomy and donate as much as you can! Share the podcast with your friends and send the Patreon link to them too! Every bit helps! Thank you! ------------------------------------ Do go visit http://astrogear.spreadshirt.com/ for cool Astronomy Cast and CosmoQuest t-shirts, coffee mugs and other awesomeness! http://cosmoquest.org/Donate This show is made possible through your donations. Thank you! (Haven't donated? It's not too late! Just click!) The 365 Days of Astronomy Podcast is produced by Astrosphere New Media. http://www.astrosphere.org/ Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org.
Það er nóg að gera hjá kartöflubændum þessi dægrin, fyrsta uppskera sumarsins kom í verslanir fyrir nokkrum dögum og útlit fyrir að uppskeran verði miklu betri en í fyrra, en það var reyndar afar dapurt sumar. Morgunvaktin sló á þráðinn til Óskars Kristinssonar kartöflubónda í Þykkvabænum Það er rétt um sólarhringur þar til úrslit í leiðtogakjöri íhaldsmanna í Bretlandi verða ljós. Enn er talið líklegast að Boris Johnson beri sigur af Jeremy Hunt. Og í Lundunúm eins og öðrum stórborgum Evrópu eru rafknúin hlaupahjól tískubóla sumarsins. Sigrún Davíðsdóttir var í vikulegu Lundúnaspjalli á Morgunvaktinni. Hið leyndardómsfulla „Svæði 51“ í eyðimörk Nevada í Bandaríkjunum hefur verið í fréttum síðustu daga, en meira en milljón manns hefur boðað komu sína á svæðið í september til þess að komast að því hvort að kenningar um að bandaríski flugherinn geymi þar fljúgandi furðuhluti og geimverur séu á rökum reistar. Flugherinn hefur ætíð neitað slíkum kenningum, að sjálfsögðu, en hvaðan koma sögusagnirnar um svæði 51 og hvað er þar í raun? Morgunvaktin fjallaði um Svæði 51. Tónlist: Ég á mig sjálf - Þuríður Sigurðardóttir Ég á mig sjálf - Megas It´s a Good Day - Peggy Lee Gypsies, Tramps & Thieves - Cher Starman - David Bowie
This is Episode 1 of our brand new second season! This is the 43rd episode since the podcast was first launched, back in February 2017, and I'm thrilled to be back on the air with you. The New Season We're mostly keeping things the same, but there are some important changes. From the beginning, I've always been pretty disorganized in how I ran the show. There was no fixed schedule or plan, so I'd release episodes as they became available. This meant that new episodes would only come out whenever it was convenient for me. Listeners like you would never know in advance when the next one would be coming out. At the end of Each episode, I'd make a promise for the next release date, but these dates were always based more on hope and ambition than on any real plan. And while this was all very charming and artisanal, it wasn't how I wanted to present myself. So now we have seasons! Everything is planned in advance, content is written and recorded to a fixed schedule, and you get your episodes when you expect them. Which, in this case, means every fortnight, for 12 episodes. But aside from these changes to scheduling and process, everything else should be much the same. Some episodes will be interviews with interesting people connected to South African astronomy. Others will be loaded with the Science Explainy Stuff that so many of you have written to ask about. Apparently those are very popular, so you're going to get a lot more of them. The only thing that I've had to cut, sadly, is the space mission updates. Clem Unger, my friend and part-time co-host, has unfortunately had to step back for a while. He was always far more interested in the various spacecraft traveling out in the Solar System, exploring and doing science, and knew far more about the subject than me. So, until he's able to rejoin the show, we're going to be silent on that subject. Dr Wendy Williams This episode features an interview with Dr Wendy Williams, a radio astronomer from Cape Town who currently works in the Netherlands, for the university of Leiden. She works with the LOFAR array, which scans the skies at the same range frequencies as used by broadcast TV, air liners, and police radios. We spoke about her current research, she taught me how these arrays of radio antennas work together to create an image, astronomy development in Africa, and more. But before I play you that interview, a quick note on audio quality. Since we were in opposite hemispheres at the time of our conversation, I had to get creative with the recording. Audio quality isn't as good as I'd have liked. I think we're still quite audible, but you can definitely tell we weren't in the same room! Coming Up Next week's episode, which airs on the 16th of July, features the first in a new series of science explainy bits, where I answer a question you might never have thought to ask: Why are planets always round, and never some other shape? If you think you know, or would like to take a guess, go ahead and tweet your ideas to @uastronomer and I might read them out before I give the answer!
Plinth Guest Mix1.Chiron by Nucleus & Paradox |2.From Early by Fracture, Chimpo |3.Strumpet by Calibre|4.Lasercat by Posij |5.Misfits by Posij |6.Trust Me by Roni Size |7.Rat Trap VIP by Serum |8.UNKNOWN |9.Resonance by Fierce/Dom & Roland |10.Accidental Note (feat Consequence) by Jubei |11.Another World by Skeptical |12.Always by Spectrasoul |13.Lofar by Need For Mirrors |14.Automaton by Ed Rush, Optical |
Arnheiður Jóhannsdóttir framkvæmdastjóri Markaðsstofu norðurlands ræddi við okkur um skíðafærið fyrir norðan um páskana
When you think of a telescope you might picture a long tube with lenses, mirrors and a tripod picking up the light that is visible to us. But there are actually several different types that pick up other wavelengths we can’t see. Dotted across Europe, the The Low Frequency Array (LOFAR) radio telescope network is attempting to map the entire night sky, and one of them located right here in Ireland. Sean Mooney, PhD student at UCD School of Physics and member of the LOFAR Surveys Key Science Project joins Jonathan in studio to discuss.
This week features the chat with David Baker and a rundown of all the week's space news. Space Quote Carl Sagan On this Day? 70th Birthday 300,000 new galaxies Elon musk / Pewdie Pie New moon found in our solar system as scientists unveil 'Hippocamp' Space Word OTW Coriolis Slavery spotted from space BereSheet Guest: David Baker Space Fact: Galaxy plates Space Song playlist on spotify bit.ly/spacesongs If you enjoy the show please go over to www.Patreon.com/Interplanetary and become a Patron or even a producer of the show. If you enjoy why not join the BIS at www.bis-space.com the oldest space advocacy organisation in the world. Subscribe on iTunes itunes.apple.com/podcast/id1097505801 Subscribe on Stitcher www.stitcher.com/podcast/interplanetary-podcast Hosts: Matt Russell and Jamie Franklin Music: Matt Russell / Iam7 Additional Narration: George Russell www.interplanetary.org.uk @interplanetypod
LOFAR - het Europese netwerk van radiotelescopen onder leiding van Nederlandse astronomen van ASTRON - heeft letterlijk een gigantische ontdekking gedaan. Maar liefst honderdduizenden nieuwe sterrenstelsels werden in kaart gebracht. De totale verzamelde data is zo groot dat je tien miljoen dvd's nodig zou hebben om al de gegevens op te slaan. En toch heeft het netwerk nog maar twee procent van de hemel gescand. Veel van de ontdekte sterrenstelsels behoren bovendien tot de eerste sterrenstelsels die ooit zijn ontstaan (zo'n 13 miljard jaar geleden, wat relatief dicht in de buurt van de oerknal is). Wat hopen de astronomen van hun ontdekkingen (al meteen goed voor 26 wetenschappelijke papers) te leren? En hoe zullen we ooit al deze gegevens kunnen analyseren? We vragen het aan sterrenkundige Huub Röttgering (Universiteit Leiden), de verantwoordelijke onderzoeksleider van dit LOFAR-project.
Vanessa and her Cosmic PuddingEpisode 41:In this episode, Tom talks with the Vanessa Moss, Astronomer extra-ordinaire. Vanessa knows her telescopes and was very informative to talk to. We chatted about STEM, Astronomy (lots of astronomy!), dancing Christmas puddings, Science communication and we said hello to our juice!You might remember Vanessa from our June 2016 STEMpunk quiz show, and you can hear it here or over on iTunes etc. Vanessa follows the worldwide adventures of the Cosmic Pudding who you can find at the Cosmic Pudding's YouTube channelVanessa answered Ben Newsome's question of "What would you do with $10m?" and asked her own question: How do we increase the science literacy for EVERYBODY, not just the already engaged? Thanks so much to Vanessa for her time, that was great interview, lots of fun, good times.In late July, STEMpunk producer and host Tom Gordon will be at the Splendour in the Grass Science Tent. You'll here about this more very soon, but in short we'll be doing some interviews with some STEM, comedy and music people, as well as some voxpops and special events such as panels and debates. It's pretty exciting, stay tuned.STEMpunk will be running another STEM based Trivia and entertainment and variety Night "STEMquiz" on Tuesday in Science week on Tuesday August 14, hosted by our friends at the wonderful Wayward Brewing Company. Details for tickets are on our Facebook page or Eventbrite.You can Find Vanessa on Twitter here: @cosmic_pudding, and some of Vanessa's projects at ASTRON, LOFAR & APERTIFIntro: STARSET -Down with the fallen.Outro: Cameron Stiff's trackBoth used with permission.STEMpunk PodcastLook: Website, Twitter, Facebook, AEON.net.auListen: iTunes, Stitcher, PlayerFM
Jafnaðarmenn í Þýskalandi hafa ákveðið að ganga til viðræðna við Kristilega demókrata um áframhaldandi stjórnarsamstarf. Aðrir möguleikar um myndun nýrrar ríkisstjórnar að loknum kosningum hafa ekki fundist. Ákvörðun Jafnaðarmanna, sem áður höfðu þverttekið fyrir að endurnýja stjórn með Kristilegum, vekur spurningar um það fyrir hvað flokkurinn stendur. Arthúr Björgvin Bollason ræddi stöðuna í stjórnmálum í Þýskalandi. Geðheilbrigðismál hafa á síðustu misserum fengið meiri athygli en áður. Ætli megi ekki tala um nokkurs konar vakningu. Margt fólk hefur þar lagt lóð á vogarskálar, ekki síst sjúklingarnir sjálfir, aðstandendur og félagasamtök. Ný ríkisstjórn ætlar að hrinda í framkvæmd geðheilbrigðisáætlun til ársins 2020, efla geðheilbrigðisþjónustu á heilsugæslustöðvum og sjúkrahúsum. Bráða- og barna- og unglingageðdeildum Landspítalans verður tryggt fjármagn til að standa undir rekstri þeirra. Svandís Svavarsdóttir, heilbrigðisráðherra, lýsti þessum áformum. Formaður Félags markþjálfa, Ásta Guðbrandsdóttir, ræddi þörfina fyrir því að hjálpa börnum og fullorðnum til að gera sitt besta, ná tengslum við tilfinningar sínar og virkja getuna. Þau sem kveiktu á Útvarpinu morguninn 23. janúar 1973, fyrir sléttum 45 árum, heyrðu þulinn og fréttamenn lýsa því að eldgos væri hafið á Heimaey. Nú er starfrækt þar glæsilegt gosminjasafn, Eldheimar, þar sem gestirganga aftur til fá tækifæri til að lifa sig inn í þessa mögnuðu atburði. Safnstjóri Eldheima, Kristín Jóhannsdóttir, rifjaði upp gosnóttina, lýsti safninu og samgöngum Eyjamanna. Elly Vilhjálms söng Ég veit þú kemur eftir Oddgeir Kristjánsson og Ása í Bæ.
On this episode, we talked about quasars, long baseline interferometry, radioastronomy, the Hubble Space Telescope, LOFAR telescope in the Netherland, the theory of the Steady State, Challenger disaster, Jan Oort, the Universe Awareness program, and so much more. The guest for today’s episode is Gorge Miley. The post The evolution of astronomy in the last 50 years [Astro et al Ep.4] appeared first on Astronomy et al.
Chris and Rob talk about advanced robotics, supernovae in M82, and the rise and fall of the BICEP2 results. There are Yellowballs in the Milky Way, and a lovely Philae GIF.Links:Philae GIF http://www.theverge.com/2015/1/30/7953217/philae-lander-descent-comet-67p-esa-rosettaThe BICEP bubbles bursts https://telescoper.wordpress.com/2015/01/30/the-bicep2-bubble-bursts/ and http://sci.esa.int/planck/55362-planck-gravitational-waves-remain-elusive/M82 from LOFAR: http://www.chalmers.se/en/centres/oso/news/Pages/Lofars-record-sharp-image-gives-astronomers–a-new-view-of-galaxy-M-82.aspxYellowballs: http://www.jpl.nasa.gov/news/news.php?feature=4462A nice merger : http://www.spacetelescope.org/news/heic1503/A movie of a laser beam pulse at super high frame rate: https://www.youtube.com/watch?v=Uq0H4-nvBB8Making robots that can do better than us http://io9.com/atlas-the-pentagons-humanoid-robot-just-got-a-major-u-1680654984MWP made APOD http://apod.nasa.gov/apod/ap150131.html with the Yellow balls[MP3 Link]Episode #131. If you have anything you’d like us to look at, or any questions you’d like us to answer - use the links at the top of the web page at http://recycledelec.com. Follow us on Twitter @recycledelec @orbitingfrog and @chrislintott.Credits:Audio content Copyright 2011-2015 Chris Lintott and Robert Simpson. Many thanks to Oxford Press Office for recording space. Podcast Image of lightbulb courtesy of Flickr user bazik (http://www.flickr.com/photos/bazik/395792175/).
Pulsars and Comets Everywhere. In the show this time, we talk to Dr. Scott Ransom about the International Pulsar Timing Array [13:53 - 30:18], Sally Cooper tells us about hunting pulsars with the LOFAR telescope in this month's JodBite [01:00 - 13:47], and your astronomy questions are answered by Dr. Joe Zuntz in Ask an Astronomer [44:11 - 49:59].
Pulsars and Comets Everywhere. In the show this time, we talk to Dr. Scott Ransom about the International Pulsar Timing Array [13:53 - 30:18], Sally Cooper tells us about hunting pulsars with the LOFAR telescope in this month's JodBite [01:00 - 13:47], and your astronomy questions are answered by Dr. Joe Zuntz in Ask an Astronomer [44:11 - 49:59].
Is SETA really just local SETI? It makes sense to me, and to Alan Penny, coordinator of the UK SETI REsearch Network. We talk to Dr. Penny about the future of SETI. Then, we talk to another Scottish astronomer Duncan Lunan about the scientific mystery of the Long Delay Echoes. Are the LDEs from a Bracewell Probe? Music by DJ Spooky, Jason Robinson, Erika Lloyd and George Hrab Detailed Show Notes
Schwerpunkt: Marcus Brüggen von der Universität Hamburg über das „Low Frequency Array”, mit dem Astronomen den Himmel im Radiobereich erforschen || Nachrichten: Rosetta in Bahn um Kometen eingeschwenkt | Neue Produktionsmethode liefert identische Nanoröhrchen | Rätselhaften Sternexplosionen auf der Spur
Fakultät für Physik - Digitale Hochschulschriften der LMU - Teil 04/05
This thesis unifies several studies, which all are dedicated to the subject of statistical data analysis in radio astronomy and radio astrophysics. Radio astronomy, like astronomy as a whole, has undergone a remarkable development in the past twenty years in introducing new instruments and technologies. New telescopes like the upgraded VLA, LOFAR, or the SKA and its pathfinder missions offer unprecedented sensitivities, previously uncharted frequency domains and unmatched survey capabilities. Many of these have the potential to significantly advance the science of radio astrophysics and cosmology on all scales, from solar and stellar physics, Galactic astrophysics and cosmic magnetic fields, to Galaxy cluster astrophysics and signals from the epoch of reionization. Since then, radio data analysis, calibration and imaging techniques have entered a similar phase of new development to push the boundaries and adapt the field to the new instruments and scientific opportunities. This thesis contributes to these greater developments in two specific subjects, radio interferometric imaging and cosmic magnetic field statistics. Throughout this study, different data analysis techniques are presented and employed in various settings, but all can be summarized under the broad term of statistical infer- ence. This subject encompasses a huge variety of statistical techniques, developed to solve problems in which deductions have to be made from incomplete knowledge, data or measurements. This study focuses especially on Bayesian inference methods that make use of a subjective definition of probabilities, allowing for the expression of probabilities and statistical knowledge prior to an actual measurement. The thesis contains two different sets of application for such techniques. First, situations where a complicated, and generally ill-posed measurement problem can be approached by assuming a statistical signal model prior to infer the desired measured variable. Such a problem very often is met should the measurement device take less data then needed to constrain all degrees of freedom of the problem. The principal case investigated in this thesis is the measurement problem of a radio interferometer, which takes incomplete samples of the Fourier transformed intensity of the radio emission in the sky, such that it is impossible to exactly recover the signal. The new imaging algorithm RESOLVE is presented, optimal for extended radio sources. A first showcase demonstrates the performance of the new technique on real data. Further, a new Bayesian approach to multi-frequency radio interferometric imaging is presented and integrated into RESOLVE. The second field of application are astrophysical problems, in which the inherent stochas- tic nature of a physical process demands a description, where properties of physical quanti- ties can only be statistically estimated. Astrophysical plasmas for instance are very often in a turbulent state, and thus governed by statistical hydrodynamical laws. Two studies are presented that show how properties of turbulent plasma magnetic fields can be inferred from radio observations.
In this talk Dr Matt Jarvis talks about radio astronomy.
In this talk Dr Matt Jarvis talks about radio astronomy.
How can we solve the space debris problem? What will we learn from LOFAR? This edition of Naked Astronomy comes from the RAL Space Conference at the STFC's Rutherford Appleton Laboratories. We'll explore the crossover between space science and medicine, catch up with Curiosity and find out how a new satellite helps to test the latest tech. Like this podcast? Please help us by supporting the Naked Scientists
How can we solve the space debris problem? What will we learn from LOFAR? This edition of Naked Astronomy comes from the RAL Space Conference at the STFC's Rutherford Appleton Laboratories. We'll explore the crossover between space science and medicine, catch up with Curiosity and find out how a new satellite helps to test the latest tech. Like this podcast? Please help us by supporting the Naked Scientists
Flat-packed. In this LOFAR-themed episode, we talk to Dr Neal Jackson [08:55 - 23:35] about the Low Frequency Array itself, Dr Tom Hassall [23:47-30:52] tells us about using it to detect pulsars and Anna Kapinska [31:01-39:12] discusses how it can be used to study active galactic nuclei. Megan rounds up the latest news [01:10 - 08:46] and we find out what's in the March night sky from Ian Morison and John Field [48:33 - 66:10].
Flat-packed. In this LOFAR-themed episode, we talk to Dr Neal Jackson [08:55 - 23:35] about the Low Frequency Array itself, Dr Tom Hassall [23:47-30:52] tells us about using it to detect pulsars and Anna Kapinska [31:01-39:12] discusses how it can be used to study active galactic nuclei. Megan rounds up the latest news [01:10 - 08:46] and we find out what's in the March night sky from Ian Morison and John Field [48:33 - 66:10].
Einstein. In this show we talk to Dr Karen Masters about LOFAR and Galaxy Zoo [00:44 - 11:07], Dr Haley Gomez talks about dust in galaxies [11:14 - 17:48] and Dr Stephen Serjeant tells us about star-forming galaxies and strong gravitational lensing [18:06 - 45:59]. Dr Tim O'Brien answers your astronomical questions [51:52 - 76:37], and we report on some odds and ends from the world of astrophysics.
Einstein. In this show we talk to Dr Karen Masters about LOFAR and Galaxy Zoo [00:44 - 11:07], Dr Haley Gomez talks about dust in galaxies [11:14 - 17:48] and Dr Stephen Serjeant tells us about star-forming galaxies and strong gravitational lensing [18:06 - 45:59]. Dr Tim O'Brien answers your astronomical questions [51:52 - 76:37], and we report on some odds and ends from the world of astrophysics.
In this special podcast from the National Astronomy Meeting in Llandudno, we hear how twisted sunspots cause solar flares, how 17th century poetry can put a date on a supernova, and why some pulsars are part-timers. We'll find out how CANDELS and LOFAR can probe the early universe, while DEBRIS looks for dusty disks around stars. Plus, we shed light on your solar science questions! Like this podcast? Please help us by supporting the Naked Scientists
In this special podcast from the National Astronomy Meeting in Llandudno, we hear how twisted sunspots cause solar flares, how 17th century poetry can put a date on a supernova, and why some pulsars are part-timers. We'll find out how CANDELS and LOFAR can probe the early universe, while DEBRIS looks for dusty disks around stars. Plus, we shed light on your solar science questions! Like this podcast? Please help us by supporting the Naked Scientists
In the show this time we find out about searches for extraterrestrial intelligence using LOFAR [12:39-20:40] and hear about SOFIA [21:06-31:52] - a telescope which is mounted on a plane. With the Māori new year approaching, we get a New Zealand view on some familiar celestial objects [32:05-41:13]. As always, Megan brings us the latest news [02:34-12:26] and Ian Morison tells us what we can see in the June night sky [43:43-58:05].
In the show this time we find out about searches for extraterrestrial intelligence using LOFAR [12:39-20:40] and hear about SOFIA [21:06-31:52] - a telescope which is mounted on a plane. With the Māori new year approaching, we get a New Zealand view on some familiar celestial objects [32:05-41:13]. As always, Megan brings us the latest news [02:34-12:26] and Ian Morison tells us what we can see in the June night sky [43:43-58:05].
Transcript -- The latest technology can look almost all the way back to the Big Bang, and may soon identify the first stars and galaxies
The latest technology can look almost all the way back to the Big Bang, and may soon identify the first stars and galaxies
It's Nick's last episode of the Jodcast and Dave makes a return after his Indian trip. In this episode we hear about finding planets with the upcoming LOFAR radio telescope from Dr Ian Stevens [09:55 - 21:29]. As always, Megan brings us the latest news [01:40 - 14:02] and Ian Morison tells us what we can see in the April night sky [21:43 - 37:06].
It's Nick's last episode of the Jodcast and Dave makes a return after his Indian trip. In this episode we hear about finding planets with the upcoming LOFAR radio telescope from Dr Ian Stevens [09:55 - 21:29]. As always, Megan brings us the latest news [01:40 - 14:02] and Ian Morison tells us what we can see in the April night sky [21:43 - 37:06].
It's the last show before Christmas so the show is a little shorter than usual. First up we bring news of two special video episode that will be out in the next few days. In our interview [04:27-27:17] we talk to Philip Best about galaxies and a new low-frequency telescope named LOFAR. We also bring you some stocking filler ideas [28:27-32:37] and round-up the feedback we've received since the last show.
It's the last show before Christmas so the show is a little shorter than usual. First up we bring news of two special video episode that will be out in the next few days. In our interview [04:27-27:17] we talk to Philip Best about galaxies and a new low-frequency telescope named LOFAR. We also bring you some stocking filler ideas [28:27-32:37] and round-up the feedback we've received since the last show.
Die Hoffnungen sind gewaltig, aber den Leistungen von Quantencomputern scheinen auch deutliche Grenzen gesetzt zu sein. Andererseits könnten sie ganz neue physikalische Grundprinzipien offenbaren. Außerdem im Gespräch: Rainer Beck, der über LOFAR berichtet – ein sehr ungewöhnliches Teleskop.