Search Publications
Searching for similarities in the accretion flow of Seyfert 1 galaxies and cataclysmic variables based on the flare profiles of IRAS 13224–3809, 1H 0707–495, Mrk 766, and MV Lyr
Dobrotka, A.; Negoro, H.; Bezák, P.
Aims. We studied the fast variability of three selected active galactic nuclei (AGNs), IRAS 13224‑3809, 1H 0707‑495, and Mrk 766, and the cataclysmic variable MV Lyr, which were observed by the XMM-Newton and Kepler spacecrafts, respectively. Our goal is to search for the common origin of the variability and to test the so-called sandwich model, i…
Identifying and fitting eclipse maps of exoplanets with cross-validation
Kreidberg, Laura; Parmentier, Vivien; Hammond, Mark +10 more
Eclipse mapping uses the shape of the eclipse of an exoplanet to measure its two-dimensional structure. Light curves are mostly composed of longitudinal information, with the latitudinal information only contained in the brief ingress and egress of the eclipse. This imbalance can lead to a spuriously confident map, where the longitudinal structure…
Is quasar variability regulated by the close environment of accretion?
Wang, Jun-Xian; Kang, Wen-Yong; Wu, Liang +1 more
Ultraviolet (UV)/optical variability in quasars is a well-observed phenomenon, yet its primeval origins remain unclear. This study investigates whether the accretion disc turbulence, which is responsible for UV/optical variability, is influenced by the close environment of the accretion by analysing the correlation between variability and infrared…
Probing Populations of Dark Stellar Remnants in the Globular Clusters 47 Tuc and Terzan 5 Using Pulsar Timing
Baumgardt, Holger; Smith, Peter J.; Hénault-Brunet, Vincent +2 more
We present a new method to combine multimass equilibrium dynamical models and pulsar timing data to constrain the mass distribution and remnant populations of Milky Way globular clusters (GCs). We first apply this method to 47 Tuc, a cluster for which there exists an abundance of stellar kinematic data and which is also host to a large population …
Calibration of the JAGB method for the Magellanic Clouds and Milky Way from Gaia DR3, considering the role of oxygen-rich AGB stars
Girardi, L.; Boyer, M. L.; Magnus, E. +3 more
The JAGB method is a new way of measuring distances in the Universe with the use of asymptotic giant branch (AGB) that are situated in a selected region in a J versus J ‑ Ks colour–magnitude diagram (CMD), and relying on the fact that the absolute J magnitude is (almost) constant. It is implicitly assumed in the method that the selected…
A Comprehensive Catalog of UVIT Observations. I. Catalog Description and First Release of Source Catalog (UVIT DR1)
Pradhan, Ananta C.; Piridi, Sonika; Kumar, Ranjan +1 more
We present the first comprehensive source catalog (UVIT DR1) of ultraviolet (UV) photometry in four far-UV (FUV ∼ 1300‑1800 Å) and five near-UV (NUV ∼ 2000‑3000 Å) filters of the Ultraviolet Imaging Telescope (UVIT) on board AstroSat. UVIT DR1 includes bright UV sources in 291 fields that UVIT detected during its first 2 yr of pointed observation,…
The Visual Monitoring Camera (VMC) on Mars Express: A new science instrument made from an old webcam orbiting Mars
Hernández-Bernal, Jorge; Cardesín-Moinelo, Alejandro; Hueso, Ricardo +17 more
The Visual Monitoring Camera (VMC) is a small imaging instrument onboard Mars Express with a field of view of ∼40°x30°. The camera was initially intended to provide visual confirmation of the separation of the Beagle 2 lander and has similar technical specifications to a typical webcam of the 2000s. In 2007, a few years after the end of its origin…
Efficient Point-spread Function Modeling with ShOpt.jl: A Point-spread Function Benchmarking Study with JWST NIRCam Imaging
Casey, Caitlin M.; Kartaltepe, Jeyhan S.; Koekemoer, Anton M. +14 more
With their high angular resolutions of 30–100 mas, large fields of view, and complex optical systems, imagers on next-generation optical/near-infrared space observatories, such as the Near-Infrared Camera (NIRCam) on the James Webb Space Telescope, present new opportunities for science and also new challenges for empirical point-spread function (P…
Climbing the Cliffs: Classifying Young Stellar Objects in the Cosmic Cliffs JWST Data Using a Probabilistic Random Forest
Di Francesco, J.; Crompvoets, B. L.; Teimoorinia, H. +1 more
Among the first observations released to the public from the JWST was a section of the star-forming region NGC 3324 known colloquially as the "Cosmic Cliffs." We build a photometric catalog of the region and test the ability of using the probabilistic random forest machine-learning method to identify its young stellar objects (YSOs). We find 450 c…
Resolving the pulsation contents of 13 δ Scuti stars with TESS and K2
Zhou, Ai-Ying
Using the TESS and Kepler K2 light curve archives, I have reanalyzed 13 known δ Scuti stars. AD Ari is now reclassified as a rotating ellipsoidal binary variable. EX Cnc and HD 73712 are reclassified as hybrid δ Sct-γ Dor pulsators. EX Cnc turns out to be an enticing asteroseismic target because of its three distinct groups of pulsation frequencie…