Search Publications
Resolving the binary components of the outbursting protostar HBC 494 with ALMA
Herczeg, Gregory J.; Zhu, Zhaohuan; Pérez, Sebastián +15 more
Episodic accretion is a low-mass pre-main sequence phenomenon characterized by sudden outbursts of enhanced accretion. These objects are classified into two: protostars with elevated levels of accretion that lasts for decades or more, called FUors, and protostars with shorter and repetitive bursts, called EXors. HBC 494 is a FUor object embedded i…
X-shooter survey of young intermediate-mass stars - I. Stellar characterization and disc evolution
Pascucci, Ilaria; Petr-Gotzens, Monika G.; Panić, Olja +6 more
Intermediate-mass stars (IMSs) represent the link between low-mass and high-mass stars, and cover a key mass range for giant planet formation. In this paper, we present a spectroscopic survey of 241 young IMS candidates with IR-excess, the most complete unbiased sample to date within 300 pc. We combined VLT/X-Shooter spectra with BVR photometric o…
A geometric calibration of the tip of the red giant branch in the Milky Way using Gaia DR3
Lidman, C.; Flynn, C.; Dixon, M. +3 more
We use the latest parallaxes measurements from Gaia DR3 to obtain a geometric calibration of the tip of the red giant branch (TRGB) in Cousins I magnitudes as a standard candle for cosmology. We utilize the following surveys: SkyMapper DR3, APASS DR9, ATLAS Refcat2, and Gaia DR3 synthetic photometry to obtain multiple zero-point calibrations of th…
Progenitors and explosion properties of supernova remnants hosting central compact objects: II. A global systematic study with a comparison to nucleosynthesis models
Fryer, C. L.; Safi-Harb, S.; Braun, C. +1 more
Core-collapse explosions of massive stars leave behind neutron stars, with a known diversity that includes the 'Central Compact Objects' (CCOs). Typified by the neutron star discovered near the centre of the Cas A supernova remnant (SNR), CCOs have been observed to shine only in X-rays. To address their supernova progenitors, we perform a systemat…
A closer look at the binary content of NGC 1850
Dreizler, S.; Usher, C.; Bastian, N. +7 more
Studies of young clusters have shown that a large fraction of O-/early B-type stars are in binary systems, where the binary fraction increases with mass. These massive stars are present in clusters of a few Myr, but gradually disappear for older clusters. The lack of detailed studies of intermediate-age clusters has meant that almost no informatio…
Infall and outflow towards high-mass starless clump candidates
Leurini, S.; Traficante, A.; Wyrowski, F. +6 more
The evolutionary sequence for high-mass star formation starts with massive starless clumps that go on to form protostellar, young stellar objects and then compact H II regions. While there are many examples of the three later stages, the very early stages have proved to be elusive. We follow-up a sample of 110 mid-infrared dark clumps selected fro…
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…
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…