Search Publications
Comparing SCUBA-2 and ALMA Selections of Faint Dusty Star-forming Galaxies in A2744
Barger, A. J.; Cowie, L. L.; McKay, S. J.
We make a comparison of deep SCUBA-2 450 and 850 µm imaging on the massive lensing cluster field A2744 with Atacama Large Millimeter/submillimeter Array (ALMA) 1.2 mm data. Our primary goal is to assess how effective the wider-field SCUBA-2 sample, in combination with red JWST priors, is for finding faint dusty star-forming galaxies (DSFGs) …
Seismic differences between solar magnetic cycles 23 and 24 for low-degree modes
García, R. A.; Mathur, S.; Salabert, D. +4 more
Solar magnetic activity follows regular cycles of about 11 years with an inversion of polarity in the poles every ∼22 years. This changing surface magnetism impacts the properties of the acoustic modes. The acoustic mode frequency shifts are a good proxy of the magnetic cycle. In this Letter we investigate solar magnetic activity cycles 23 and 24 …
Ultraviolet spectroscopy of the supernova Ia hypervelocity runaway white dwarf J0927‑6335
El-Badry, Kareem; Gänsicke, Boris T.; Shen, Ken J. +1 more
The hot white dwarf (WD) J0927‑6335 (Gaia DR3 5250394728194220800 with an effective temperature of Teff = 60 000 K and a surface gravity of logg = 7) was detected as the fastest known Galactic hypervelocity star with a space velocity of ≈2800 km s‑1 and an atmosphere dominated by carbon and oxygen. It is thought to be the sur…
WISDOM Project - XIX. Figures of merit for supermassive black hole mass measurements using molecular gas and/or megamaser kinematics
Williams, Thomas G.; Cappellari, Michele; Davis, Timothy A. +7 more
The mass (MBH) of a supermassive black hole (SMBH) can be measured using spatially resolved kinematics of the region where the SMBH dominates gravitationally. The most reliable measurements are those that resolve the smallest physical scales around the SMBHs. We consider here three metrics to compare the physical scales probed by kinema…
Observed epochal variations in X-ray lines from the O supergiant ζ Puppis do not require substantial changes in the wind mass flux
Huenemoerder, David P.; Miller, Nathan A.; Pradhan, Pragati +2 more
We fit the high-resolution Chandra X-ray spectra of the O supergiant ζ Puppis using the variable boundary condition (VBC) line model to test the stability of its mass-loss rate between two epochs of observation: 2000 March and 2018 July - 2019 August. At issue is whether the observed variations are induced by global changes in the cool (unshocked)…
CONGRUENTS (COsmic-ray, Neutrino, Gamma-ray and Radio Non-Thermal Spectra) - II. Population-level correlations between galactic infrared, radio, and γ-ray emission
Thompson, Todd A.; Krumholz, Mark R.; Crocker, Roland M. +1 more
Galaxies obey a number of empirical correlations between their radio, γ-ray, and infrared emission, but the physical origins of these correlations remain uncertain. Here, we use the CONGRUENTS model for broad-band non-thermal emission from star-forming galaxies, which self-consistently calculates energy-dependent transport and non-thermal emission…
Open superclusters. I. The most populated primordial groups of open clusters in the third quadrant of the Galactic disk
Casado, Juan; Hendy, Yasser
We define an open supercluster (OSC) as a cluster of at least six open clusters (OCs) born from the same giant molecular cloud (GMC). We surveyed the recent catalogs of OCs based on Gaia data and relevant literature to find 17 OSCs of the third Galactic quadrant, along with 190 likely members of them. OSCs are frequent enough to be considered an e…
Growing a nuclear star cluster from star formation and cluster mergers: The JWST NIRSpec view of NGC 4654
Arribas, Santiago; Bunker, Andrew J.; Lützgendorf, Nora +10 more
We present a detailed study of the centre of NGC 4654, a Milky Way-like spiral galaxy in the Virgo cluster that has been reported to host a double stellar nucleus, thus promising a rare view of ongoing star cluster infall into a galaxy nucleus. Analysing JWST NIRSpec integral-field spectroscopic data in combination with Hubble Space Telescope Wide…
Testing the surface brightness fluctuation method on dwarf galaxies in the COSMOS field
Taylor, James E.; Blakeslee, John P.; Foster, Lauren M.
Dwarf galaxies are important tracers of small-scale cosmological structure, yet much of our knowledge about these systems comes from the limited sample of dwarf galaxies within the Local Group. To make a comprehensive inventory of dwarf populations in the local Universe, we require effective methods for deriving distance estimates for large number…
A spectroscopic and kinematic survey of fast hot subdwarfs
Rauch, T.; Geier, S.; Gänsicke, B. T. +19 more
Hot subdwarfs (sdO/B) are the stripped helium cores of red giants formed via binary interactions. Close hot subdwarf binaries with massive white dwarf companions have been proposed as possible progenitors of thermonuclear supernovae type Ia (SN Ia). If the supernova is triggered by stable mass transfer from the helium star, the companion should su…