Search Publications
J-PLUS: galaxy-star-quasar classification for DR3
Hernández-Monteagudo, C.; Alvarez-Candal, A.; Vázquez Ramió, H. +20 more
The Javalambre Photometric Local Universe Survey (J-PLUS) is a 12-band photometric survey using the 83-cm JAST telescope. Data Release 3 includes 47.4 million sources. J-PLUS DR3 only provides star-galaxy classification so that quasars are not identified from the other sources. Given the size of the data set, machine learning methods could provide…
Finding accreted stars in the Milky Way: clues from NIHAO simulations
Buder, S.; Mijnarends, L.; Buck, T.
Exploring the marks left by galactic accretion in the Milky Way helps us understand how our Galaxy was formed. However, finding and studying accreted stars and the galaxies they came from has been challenging. This study uses a simulation from the Numerical Investigation of a Hundred Astronomical Objects project, which now includes a wider range o…
Characterizing cool, neutral gas, and ionized metals in the outskirts of low-z galaxy clusters
Muzahid, Sowgat; Charlton, Jane; Srianand, Raghunathan +2 more
We present the first detection of cool, neutral gas in the outskirts of low-z galaxy clusters using a statistically significant sample of 3191 z ≈ 0.2 background quasar-foreground cluster pairs by cross-matching the Hubble Spectroscopic Legacy Archive quasar catalogue with optically- and SZ-selected cluster catalogues. The median cluster mass of o…
A radio bubble shredded by gas sloshing?
Brunetti, G.; Shimwell, T. W.; Bartalucci, I. +7 more
We report on the detection of diffuse radio emission with peculiar morphology in the central region of the galaxy cluster Abell 2657. The most striking feature identified in our 144 MHz LOFAR image is a bifurcated radio arc that extends for a projected size of 150-200 kpc. From the analysis of XMM-Newton data, we find clear evidence of gas sloshin…
SMART: spectral energy distributions Markov chain analysis with radiative transfer models
Efstathiou, Andreas; Varnava, Charalambia
In this paper we present the publicly available open-source spectral energy distribution (SED) fitting code SMART (Spectral energy distributions Markov chain Analysis with Radiative Transfer models). Implementing a Bayesian Markov chain Monte Carlo (MCMC) method, SMART fits the ultraviolet to millimetre SEDs of galaxies exclusively with radiative …
Shock-driven synchrotron radio emission from the 2021 outburst of RS Ophiuchi
Singh, Kulinder Pal; Anupama, G. C.; Sonith, L. S. +4 more
We present low-frequency radio observations of the Galactic symbiotic recurrent nova RS Ophiuchi during its 2021 outburst. The observations were carried out with the upgraded Giant Metrewave Radio Telescope spanning a frequency range of 0.15-1.4 GHz during 23-287 d post the outburst. The average value of the optically thin spectral index is α ~ -0…
Search for brown dwarfs in IC 1396 with Subaru HSC: interpreting the impact of environmental factors on substellar population
Jose, Jessy; Samal, Manash R.; Guo, Zhen +4 more
Young stellar clusters are predominantly the hub of star formation and hence, ideal to perform comprehensive studies over the least explored substellar regime. Various unanswered questions like the mass distribution in brown dwarf regime and the effect of diverse cluster environment on brown dwarf formation efficiency still plague the scientific c…
TIC 184 743 498: the first tri-axial stellar pulsator
Jayaraman, Rahul; Handler, Gerald; Rappaport, Saul +4 more
We have discovered a δ Scuti pulsator in a tight binary (P = 1.053 d) with nine pulsation modes whose frequencies are between 38 and 56 d-1. Each of these modes exhibits amplitude modulations and π-rad phase shifts twice per orbital cycle. Five of these modes exhibit amplitude and phase shifts that are readily explained by dipole pulsat…
Dynamical substructures of local metal-poor halo
Shi, Jianrong; Ma, Jun; Ye, Dashuang +1 more
Based on 4098 very metal poor (VMP) stars with six-dimensional phase-space and chemical information from Gaia Data Release 3 (DR3) and Large sky Area Multi-Object fiber Spectroscopic Telescope DR9 as tracers, we apply an unsupervised machine learning algorithm, shared nearest neighbour, to identify stellar groups in the action-energy (J-E) space. …
The GALAH survey: elemental abundances in open clusters using joint effective temperature and surface gravity photometric priors
Lewis, Geraint F.; Buder, Sven; Bland-Hawthorn, Joss +10 more
The ability to measure precise and accurate stellar effective temperatures (Teff) and surface gravities (log (g)) is essential in determining accurate and precise abundances of chemical elements in stars. Measuring log (g) from isochrones fitted to colour-magnitude diagrams of open clusters is significantly more accurate and precise com…