Search Publications
UOCS XIV: Study of the Open Cluster NGC 2627 Using UVIT/AstroSat
Panthi, Anju; Vaidya, Kaushar; Saketh, Pinapati
We study the intermediate-age open cluster NGC 2627, located at a distance of ∼2 kpc, using UVIT/AstroSat and other archival data. Using a machine learning-based algorithm, ML-MOC, on the Gaia DR3 data, we identify 422 cluster members, including four blue straggler stars (BSSs), one yellow straggler star (YSS), one blue lurker (BL), one red clump …
The miniJPAS survey. Optical detection of galaxy clusters with PZWav
Finoguenov, A.; Hernán-Caballero, A.; Mendes de Oliveira, C. +21 more
Context. Galaxy clusters are an essential tool to understand and constrain the cosmological parameters of our universe. Thanks to its multi-band design, J-PAS offers a unique group and cluster detection window using precise photometric redshifts and sufficient depths.
Aims: We produced galaxy cluster catalogues from miniJPAS, which is a pathf…
MHz to TeV expectations from scotogenic WIMP dark matter
Siegert, Thomas; Eisenberger, Laura; Mannheim, Karl +1 more
The indirect search for dark matter is typically restricted to individual photon bands and instruments. In the context of multiwavelength observations, finding a weak signal in large foreground and background at only one wavelength band is hampered by systematic uncertainties dominating the signal strength. Dark matter particle annihilation is pro…
The giant outburst of EXO 2030+375. II. Broadband spectroscopy and evolution
Wolff, M. T.; Wilms, J.; Pottschmidt, K. +13 more
In 2021, the high-mass X-ray binary EXO 2030+375 underwent a giant X-ray outburst, the first since 2006, that reached a peak flux of ∼600 mCrab (3-50 keV). The goal of this work is to study the spectral evolution over the course of the outburst, search for possible cyclotron resonance scattering features (CRSFs), and to associate spectral componen…
Impact of α enhancement on the asteroseismic age determination of field stars. Application to the APO-K2 catalogue
Valle, G.; Dell'Omodarme, M.; Prada Moroni, P. G. +1 more
Aims: We investigated the theoretical biases affecting the asteroseismic grid-based estimates of stellar mass, radius, and age in the presence of a mismatch between the heavy element mixture of observed stars and stellar models.
Methods: We performed a controlled simulation adopting a stellar effective temperature, [Fe/H], an average lar…
The Gaia-ESO Survey DR5.1 and Gaia DR3 GSP-Spec: a comparative analysis
Recio-Blanco, A.; de Laverny, P.; Vallenari, A. +10 more
Context. The third data release of Gaia, has provided stellar parameters, metallicity [M/H], [α/Fe], individual abundances, broadening parameter from its Radial Velocity Spectrograph (RVS) spectra for about 5.6 million objects thanks to the GSP-Spec module, implemented in the Gaia pipeline. The catalogue also publishes the radial velocity of 33 mi…
Optical Variability of Gaia CRF3 Sources with Robust Statistics and the 5000 Most Variable Quasars
Makarov, Valeri V.
Using the light-curve time-series data for more than 11.7 million variable sources published in the Gaia Data Release 3, the average magnitudes, colors, and variability parameters have been computed for 0.836 million Gaia CRF objects, which are mostly quasars and active galactic nuclei (AGNs). To mitigate the effects of occasional flukes in the da…
Turbulent Pressure Heats Gas and Suppresses Star Formation in Galactic Bar Molecular Clouds
Meier, David S.; Ginsburg, Adam; Klessen, Ralf S. +6 more
The Central Molecular Zone (CMZ) of the Milky Way is fed by gas inflows from the Galactic disk along almost radial trajectories aligned with the major axis of the Galactic bar. However, despite being fundamental to all processes in the nucleus of the Galaxy, these inflows have been studied significantly less than the CMZ itself. We present observa…
Simultaneous Far-ultraviolet and Near-ultraviolet Observations of T Tauri Stars with UVIT/AstroSat: Probing the Accretion Process in Young Stars
Gorti, Uma; Manoj, P.; Narang, Mayank +4 more
We present results from simultaneous far-ultraviolet (FUV) and near-ultraviolet (NUV) observations of T Tauri stars (TTSs) in the Taurus molecular cloud with UVIT/AstroSat. This is the very first UVIT study of TTSs. From the spectral energy distribution of TTSs from FUV to IR, we show that classical TTSs (CTTSs) emit significantly higher UV excess…
Evolution of the dual AGN in Mrk 266: a young AGN and a rotation-dominated disc in the SW nucleus
Stern, Daniel; Comerford, Julia M.; Malkan, Matthew A. +6 more
Dual active galactic nuclei (AGNs) offer a unique opportunity to probe the relationship between supermassive black holes (SMBH) and their host galaxies as well as the role of major mergers in triggering AGN activity. The confirmed dual AGN Mrk 266 has been studied extensively with multiwavelength imaging. Now, high-spatial-resolution IFU spectrosc…