Search Publications
Milky Way globular clusters on cosmological timescales. II. Interaction with the Galactic centre
Berczik, Peter; Ishchenko, Maryna; Sobolenko, Margaryta +2 more
Aims: We estimate the dynamical evolution of the interaction of globular clusters' with the Galactic centre that dynamically changed in the past.
Methods: We simulated the orbits of 147 globular clusters over a 10 Gyr lookback time using the parallel N-body code `φ-GPU'. For each globular cluster, we generated 1000 sets of initial data w…
Unveiling the accretion scenario of BH-ULXs using XMM-Newton observations
Agrawal, Vivek K.; Nandi, Anuj; Das, Santabrata +1 more
We present a comprehensive spectrotemporal analysis of five ultraluminous X-ray sources (ULXs) with central object likely being a black hole, using archival XMM-Newton observations. These sources, namely NGC1313 X-1, NGC5408 X-1, NGC6946 X-1, M82 X-1, and IC342 X-1, reveal short-term variability with fractional variance of 1.42$-27.28~{{\ \rm per\…
Constraining the LyC escape fraction from LEGUS star clusters with SIGNALS H II region observations: a pilot study of NGC 628
Della Bruna, Lorenza; Grebel, Eva K.; Rousseau-Nepton, Laurie +23 more
The ionizing radiation of young and massive stars is a crucial form of stellar feedback. Most ionizing (Lyman-continuum; LyC, λ < 912Å) photons are absorbed close to the stars that produce them, forming compact H II regions, but some escape into the wider galaxy. Quantifying the fraction of LyC photons that escape is an open problem. In this wo…
ABYSS. I. Targeting Strategy for the APOGEE and BOSS Young Star Survey in SDSS-V
Kounkel, Marina; Stringfellow, Guy; Rojas-Ayala, Bárbara +15 more
The fifth iteration of the Sloan Digital Sky Survey is set to obtain optical and near-infrared spectra of ~5 million stars of all ages and masses throughout the Milky Way. As a part of these efforts, APOGEE and BOSS Young Star Survey (ABYSS) will observe ~105 stars with ages <30 Myr that have been selected using a set of homogeneous …
Spiral arms and the angular momentum gap in Milky Way Cepheids
Schönrich, Ralph; Dehnen, Walter; Semczuk, Marcin +1 more
The angular momentum distribution of classical Cepheids in the outer Milky Way disc is bimodal with a gap at $L_\mathrm{gap}=2950\, \rm{km\,s^{-1}}$ kpc, corresponding to $R=13\,$ kpc, while no similar feature has been found in the general population of disc stars. We show that star formation in multiple spiral arm segments at the same azimuth lea…
Hubble Space Telescope survey of Magellanic Cloud star clusters: UV-dim stars in young clusters
Di Criscienzo, M.; Milone, A. P.; Cordoni, G. +11 more
Young and intermediate-age star clusters of both Magellanic Clouds exhibit complex colour-magnitude diagrams. In addition to the extended main-sequence turn-offs (eMSTOs), commonly observed in star clusters younger than ~2 Gyr, the clusters younger than ~800 Myr exhibit split main sequences (MSs). These comprise a blue MS, composed of stars with l…
Progenitor Constraint with Circumstellar Material for the Magnetar-hosting Supernova Remnant RCW 103
Uchida, Hiroyuki; Tsuru, Takeshi Go; Tanaka, Takaaki +2 more
Stellar winds blown out from massive stars (≳10 M ⊙) contain precious information on the progenitor itself, and in this context the most important elements are carbon (C), nitrogen (N), and oxygen (O), which are produced by the CNO cycle in the H-burning layer. Although their X-ray fluorescence lines are expected to be detected in swept…
Unbound stars hold the key to young star cluster history
Pfalzner, Susanne; Arunima, Arunima; Govind, Amith
Aims.Gaia delivers the positions and velocities of stars at an unprecedented precision. Therefore, for star clusters, there exists much higher confidence in whether a specific star is a member of a particular cluster or not. However, membership determination is still especially challenging for young star clusters. At ages 2−10 Myr, the gas is expe…
Late-time Hubble Space Telescope Observations of AT 2018cow. I. Further Constraints on the Fading Prompt Emission and Thermal Properties 50-60 days Post-discovery
Kilpatrick, Charles D.; Drout, Maria R.; Foley, Ryan J. +6 more
The exact nature of the luminous fast blue optical transient AT 2018cow is still debated. In this first of a two-paper series, we present a detailed analysis of three Hubble Space Telescope (HST) observations of AT 2018cow covering ~50-60 days post-discovery in combination with other observations throughout the first two months and derive signific…
BU Canis Minoris - the most compact known flat doubly eclipsing quadruple system
Powell, Brian P.; Borkovits, Tamás; Gagliano, Robert +25 more
We have found that the 2+2 quadruple star system BU CMi is currently the most compact quadruple system known, with an extremely short outer period of only 121 d. The previous record holder was TIC 219006972 (Kostov et al.), with a period of 168 d. The quadruple nature of BU CMi was established by Volkov, Kravtsova & Chochol, but they misidenti…