Search Publications
Oxygen and iron in interstellar dust: An X-ray investigation
Waters, L. B. F. M.; Mutschke, H.; Costantini, E. +9 more
Understanding the chemistry of the interstellar medium (ISM) is fundamental for the comprehension of Galactic and stellar evolution. X-rays provide an excellent way to study the dust chemical composition and crystallinity along different sight lines in the Galaxy. In this work, we study the dust grain chemistry in the diffuse regions of the ISM in…
Low-redshift estimates of the absolute scale of baryon acoustic oscillations
Ruchika; Alcaniz, Jailson; Lemos, Thais +1 more
Measurements of the characteristic length scale
The extreme super-eddington NLS1 RX J0134.2-4258 - II. A weak-line Seyfert linking to the weak-line quasar
Done, Chris; Ward, Martin; Jin, Chichuan +3 more
RX J0134.2-4258 is one of the most super-Eddington narrow-line Seyfert 1 (NLS1) galaxies, on which we conducted a monitoring campaign from radio to X-rays. In this paper, we present a detailed analysis of its optical/UV spectra and broad-band spectral energy distribution. Our study shows that the preferred black hole mass of RX J0134.2-4258 is M
Gamma Cas Stars as Be+White Dwarf Binary Systems
Gies, Douglas R.; Wang, Luqian; Klement, Robert
The origin of the bright and hard X-ray emission flux among the γ Cas subgroup of B-emission line (Be) stars may be caused by gas accretion onto an orbiting white dwarf (WD) companion. Such Be+WD binaries are the predicted outcome of a second stage of mass transfer from a helium star mass donor to a rapidly rotating mass gainer star. The stripped …
Revisiting Galactic Disk and Spiral Arms Using Open Clusters
Joshi, Yogesh C.; Malhotra, Sagar
We use the largest catalog of open clusters in the post-Gaia era to provide an observational view of the Galactic disk. By compiling physical parameters such as age, distance, and kinematic information, we investigate the spatial distribution of open clusters and revisit the spiral arms and other asymmetries in the Galactic disk. Using young open …
The Green Bank North Celestial Cap Survey. VII. 12 New Pulsar Timing Solutions
Ransom, S. M.; Kaplan, D. L.; McLaughlin, M. A. +22 more
We present timing solutions for 12 pulsars discovered in the Green Bank North Celestial Cap 350 MHz pulsar survey, including six millisecond pulsars (MSPs), a double neutron star (DNS) system, and a pulsar orbiting a massive white dwarf companion. Timing solutions presented here include 350 and 820 MHz Green Bank Telescope data from initial confir…
A new resonance-like feature in the outer disc of the Milky Way
Fouesneau, M.; Andrae, R.; Castro-Ginard, A. +18 more
Modern astrometric and spectroscopic surveys have revealed a wealth of structure in the phase space of stars in the Milky Way, with evidence of resonance features and non-equilibrium processes. Using the third Gaia data release, we present evidence of a new resonance-like feature in the outer disc of the Milky Way. The feature is most evident in t…
An environmental analysis of the fast transient AT2018cow and implications for its progenitor and late-time brightness
Sun, Ning-Chen; Shao, Yali; Maund, Justyn R. +1 more
The nature of the newly discovered fast blue optical transients (FBOTs) is still puzzling astronomers. In this paper, we carry out a comprehensive analysis of the molecular gas, ionized gas, and stellar populations in the environment of the nearby FBOT AT2018cow based on ALMA, VLT/MUSE, and HST/WFC3 observations. A prominent molecular concentratio…
On the gravitational lensing interpretation of three gravitational wave detections in the mass gap by LIGO and Virgo
Richard, Johan; Smith, Graham P.; Massey, Richard +7 more
We search for gravitational wave (GW) events from LIGO-Virgo's third run that may have been affected by gravitational lensing. Gravitational lensing delays the arrival of GWs, and alters their amplitude - thus biasing the inferred progenitor masses. This would provide a physically well-understood interpretation of GW detections in the 'mass gap' b…
CECILIA: The Faint Emission Line Spectrum of z 2-3 Star-forming Galaxies
Maseda, Michael V.; Steidel, Charles C.; Law, David R. +7 more
We present the first results from Chemical Evolution Constrained Using Ionized Lines in Interstellar Aurorae (CECILIA), a Cycle 1 JWST NIRSpec/MSA program that uses ultra-deep ~30 hr G235M/F170LP observations to target multiple electron temperature-sensitive auroral lines in the spectra of 33 galaxies at z ~ 1-3. Using a subset of 23 galaxies, we …