Search Publications
Living with a Red Dwarf: X-Ray, UV, and Ca II Activity-Age Relationships of M Dwarfs
Engle, Scott G.
The vast majority of stars in the nearby stellar neighborhood are M dwarfs. Their low masses and luminosities result in slow rates of nuclear evolution and minimal changes to the stars' observable properties, even along astronomical timescales. However, they possess relatively powerful magnetic dynamos and resulting X-ray to UV (X-UV) activity, co…
COALAS II. Extended molecular gas reservoirs are common in a distant, forming galaxy cluster
Thomson, A. P.; Dannerbauer, H.; Seymour, N. +24 more
This paper presents the results of 475h of interferometric observations with the Australia Telescope Compact Array towards the Spiderweb protocluster at z=2.16. We search for large, extended molecular gas reservoirs among 46 previously detected CO(1-0) emitters, employing a customised method we developed. Based on the CO emission images and positi…
Multiband Simultaneous Photometry of Type II SN 2023ixf with Mephisto and the Twin 50 cm Telescopes
Kumar, Brajesh; Liu, Chenxu; Yang, Yuan-Pei +13 more
SN 2023ixf, recently reported in the nearby galaxy M101 at a distance of 6.85 Mpc, was one of the closest and brightest core-collapse supernovae in the last decade. In this work, we present multiwavelength photometric observation of SN 2023ixf with the Multi-channel Photometric Survey Telescope (Mephisto) in the uvgr bands and with the twin 50 cm …
Cloudlet capture model for the accretion streamer onto the disc of DG Tau
Codella, Claudio; Garufi, Antonio; Podio, Linda +2 more
DG Tau is a nearby T Tauri star associated with a collimated jet, a circumstellar disc, and a streamer a few hundred au long. The streamer connects to the disc at ~50 au from DG Tau. At this location SO emission is observed, likely due to the release of sulphur from dust grains caused by the shock of the impact of the accretion streamer onto the d…
Compact white dwarf binaries in the combined SRG/eROSITA/SDSS eFEDS survey
Salvato, M.; Brandt, W. N.; Merloni, A. +22 more
Context. X-ray surveys combined with optical follow-up observations are used to generate complete flux-limited samples of the main X-ray emitting source classes. eROSITA on the Spectrum-Roentgen-Gamma mission provides sufficient sensitivity to build significantly enhanced samples of rare X-ray emitting sources.
Aims: We strive to identify and…
oMEGACat. II. Photometry and Proper Motions for 1.4 Million Stars in Omega Centauri and Its Rotation in the Plane of the Sky
Dreizler, S.; Anderson, J.; Milone, A. P. +15 more
Omega Centauri (ω Cen) is the most massive globular cluster of the Milky Way. It is thought to be the nucleus of an accreted dwarf galaxy because of its high mass and its complex stellar populations. To decipher its formation history and study its dynamics, we created the most comprehensive kinematic catalog for its inner region, by analyzing both…
AT2023fhn (the Finch): a luminous fast blue optical transient at a large offset from its host galaxy
Groot, P. J.; Wiersema, K.; Levan, A. J. +8 more
Luminous fast blue optical transients (LFBOTs) - the prototypical example being AT 2018cow - are a rare class of events whose origins are poorly understood. They are characterized by rapid evolution, featureless blue spectra at early times, and luminous X-ray and radio emission. LFBOTs thus far have been found exclusively at small projected offset…
A Hubble Space Telescope Search for r-Process Nucleosynthesis in Gamma-Ray Burst Supernovae
Covino, S.; Melandri, A.; Pian, E. +24 more
The existence of a secondary (in addition to compact object mergers) source of heavy element (r-process) nucleosynthesis, the core-collapse of rapidly rotating and highly magnetized massive stars, has been suggested by both simulations and indirect observational evidence. Here, we probe a predicted signature of r-process enrichment, a late-time (≳…
Compositional Metrics of Fast and Slow Alfvénic Solar Wind Emerging from Coronal Holes and Their Boundaries
Riley, Pete; Bale, Stuart D.; Bowen, Trevor A. +7 more
We seek to understand the composition and variability of fast solar wind (FSW) and slow Alfvénic solar wind emerging from coronal holes (CHs). We leverage an opportune conjunction between Solar Orbiter and Parker Solar Probe (PSP) during PSP Encounter 11 to include compositional diagnostics from the Solar Orbiter Heavy Ion Sensor as these variatio…
The Escape Velocity Profile of the Milky Way from Gaia DR3
Necib, Lina; Ou, Xiaowei; Lin, Tongyan +2 more
The escape velocity profile of the Milky Way offers a crucial and independent measurement of its underlying mass distribution and dark matter (DM) properties. Using a sample of stars from the third data release of Gaia with 6D kinematics and strict quality cuts, we obtain an escape velocity profile of the Milky Way from 4 to 11 kpc in Galactocentr…