Search Publications
cecilia: a machine learning-based pipeline for measuring metal abundances of helium-rich polluted white dwarfs
Vanderburg, Andrew; Badenas-Agusti, Mariona; Blouin, Simon +4 more
Over the past several decades, conventional spectral analysis techniques of polluted white dwarfs have become powerful tools to learn about the geology and chemistry of extrasolar bodies. Despite their proven capabilities and extensive legacy of scientific discoveries, these techniques are, however, still limited by their manual, time-intensive, a…
The surface mass density of the Milky Way: does the traditional KZ approach work in the context of new surveys?
Majewski, Steven R.; Cheng, Xinlun; Anguiano, Borja +1 more
We revisit the classical KZ problem - determination of the vertical force and implied total mass density distribution of the Milky Way disc - for a wide range of Galactocentric radius and vertical height using chemically selected thin and thick disc samples based on Apache Point Observatory Galactic Evolution Experiment spectroscopy com…
Study of the energetic X-ray superflares from the active fast rotator AB doradus
Srivastava, A. K.; Singh, Gurpreet; Pandey, Jeewan C. +1 more
We present the analyses of intense X-ray flares detected on the active fast rotator AB Dor using observations from the XMM-Newton. A total of 21 flares are detected, and 13 flares are analysed in detail. The total X-ray energy of these flares is found to be in the range of 1034-36 erg, in which the peak flare flux increased up to 34 tim…
The properties of RR Lyrae variable stars in the Local Group dwarf galaxy LGS-3
Sarajedini, Ata
We present a sample of 56 RR Lyrae variable stars (48 ab-type and 8 c-type) measured from a set of F475W (≈B filter) and F814W (≈I filter) archival images taken with the Hubble Space Telescope/Advanced Camera for Surveys of one field in the Local Group dwarf galaxy LGS-3 (also known as the Pisces Dwarf or Pisces I). The ab-type variables exhibit a…
DEVILS/MIGHTEE/GAMA/DINGO: the impact of SFR time-scales on the SFR-radio luminosity correlation
Holwerda, Benne W.; Knowles, Kenda; Driver, Simon P. +20 more
The tight relationship between infrared luminosity (LTIR) and 1.4 GHz radio continuum luminosity ($L_\mathrm{1.4\, GHz}$) has proven useful for understanding star formation free from dust obscuration. Infrared emission in star-forming galaxies typically arises from recently formed, dust-enshrouded stars, whereas radio synchrotron emissi…
Dark lens candidates from Gaia Data Release 3
Bennett, D. P.; Soszyński, I.; Udalski, A. +48 more
Gravitational microlensing is a phenomenon that allows us to observe the dark remnants of stellar evolution, even if these bodies are no longer emitting electromagnetic radiation. In particular, it can be useful to observe solitary neutron stars or stellar-mass black holes, providing a unique window through which to understand stellar evolution. O…
Discovery of the Longest-period Classical Cepheid in the Milky Way
Soszyński, I.; Udalski, A.; Szymański, M. K. +12 more
We report the discovery of the classical Cepheid OGLE-GD-CEP-1884 (= GDS_J1535467-555656) with the longest pulsation period known in our Galaxy. The period of 78.14 days is nearly 10 days longer than that of the previous record-holding Cepheid, S Vulpeculae, and thus, OGLE-GD-CEP-1884 can be categorized as the first ultra-long-period Cepheid in th…
Magnetic Fields in M-dwarf Members of the Pleiades Open Cluster Using APOGEE Spectra
Wanderley, Fábio; Cunha, Katia; Smith, Verne V. +10 more
Average magnetic field measurements are presented for 62 M-dwarf members of the Pleiades open cluster, derived from Zeeman-enhanced Fe I lines in the H band. A Markov Chain Monte Carlo methodology was employed to model magnetic filling factors using Sloan Digital Sky Survey (SDSS) IV APOGEE high-resolution spectra, along with the radiative transfe…
Detecting the edges of galaxies with deep learning
Buitrago, Fernando; Fernández-Iglesias, Jesús; Sahelices, Benjamín
Galaxy edges or truncations are low-surface-brightness (LSB) features located in the galaxy outskirts that delimit the distance up to where the gas density enables efficient star formation. As such, they could be interpreted as a non-arbitrary means to determine the galaxy size and this is also reinforced by the smaller scatter in the galaxy mass-…
Dark Photon Dark Matter and Low-frequency Gravitational-wave Detection with Gaia-like Astrometry
Wang, Xin; Zhao, Yue; An, Haipeng +3 more
Astrometric surveys offer us a method for searching for elusive cosmic signatures, such as ultralight dark photon dark matter and gravitational waves (GWs), by observing the temporal change of stars' apparent locations. The detection capabilities of such surveys rapidly decrease at low frequencies, because the signals become hardly distinguishable…