Search Publications
ALMACAL VIII: a pilot survey for untargeted extragalactic CO emission lines in deep ALMA calibration data
Hamanowicz, Aleksandra; Lagos, Claudia del P.; Ivison, Rob J. +6 more
We present a pilot, untargeted extragalactic carbon monoxide (CO) emission-line survey using ALMACAL, a project utilizing ALMA calibration data for scientific purposes. In 33 deep (Texp > 40 min) ALMACAL fields, we report six CO emission-line detections above S/N > 4, one-third confirmed by MUSE observations. With this pilot surve…
Abundances of CNO elements in z 0.3-0.4 Lyman continuum leaking galaxies
Chisholm, J.; Schaerer, D.; Ravindranath, S. +4 more
We present observations with the Space Telescope Imaging Spectrograph onboard the Hubble Space Telescope (HST) of 11 Lyman continuum (LyC) leaking galaxies at redshifts, z, in the range 0.29-0.43, with oxygen abundances 12+log(O/H) = 7.64-8.16, stellar masses M⋆ ~ 107.8-109.8 M⊙, and O32 = [O …
Mass-ratio distribution of contact binary stars
Pejcha, Ondřej; Pešta, Milan
The mass ratio q of a contact binary star evolves through mass transfer, magnetic braking, and thermal relaxation oscillations to low values until it crosses a critical threshold qmin. When this occurs, the binary undergoes the tidal Darwin instability, leading to a rapid coalescence of the components and to an observable brightening of…
Near-IR Weak-lensing (NIRWL) Measurements in the CANDELS Fields. I. Point-spread Function Modeling and Systematics
Chary, Ranga-Ram; Taylor, Peter; Jee, M. James +5 more
We have undertaken a near-IR weak-lensing (NIRWL) analysis of the CANDELS HST/WFC3-IR F160W observations. With the Gaia proper motion–corrected catalog as an astrometric reference, we updated the astrometry of the five CANDELS mosaics and achieved an absolute alignment within 0.″02 ± 0.″02, on average, which is a factor of several superior to exis…
A major asymmetric ice trap in a planet-forming disk. IV. Nitric oxide gas and a lack of CN tracing sublimating ices and a C/O ratio <1
van der Marel, N.; van Dishoeck, E. F.; Tabone, B. +5 more
Context. Most well-resolved disks observed with the Atacama Large Millimeter/submillimeter Array (ALMA) show signs of dust traps. These dust traps set the chemical composition of the planet-forming material in these disks, as the dust grains with their icy mantles are trapped at specific radii and could deplete the gas and dust at smaller radii of…
Probing minimal grand unification through gravitational waves, proton decay, and fermion masses
Saad, Shaikh
Motivated by the direct discovery of gravitational waves (GWs) from black holes and neutron stars, there is a growing interest in investigating GWs from other sources. Among them, GWs from cosmic strings are particularly fascinating since they naturally appear in a large class of grand unified theories (GUTs). Remarkably, a series of pulsar-timing…
Evidence of an age gradient along the line of sight in the nuclear stellar disc of the Milky Way
Schultheis, M.; Rich, R. M.; Najarro, F. +3 more
Context. The nuclear stellar disc (NSD) is a flat dense stellar structure at the heart of the Milky Way. Recent work has shown that analogous structures are common in the nuclei of external spiral galaxies, where there is evidence of an age gradient that indicates that they form inside-out. However, the characterisation of the age of the NSD stell…
SRG/eROSITA discovery of a radio-faint X-ray candidate supernova remnant SRGe J003602.3+605421 = G121.1-1.9
Sunyaev, R. A.; Churazov, E. M.; Khabibullin, I. I. +2 more
We report the discovery of a candidate X-ray supernova remnant SRGe J003602.3+605421 = G121.1-1.9 in the course of the SRG/eROSITA all-sky survey. The object is located at (l, b) = (121.1°, -1.9°), is ≈36 arcmin in angular size, and has a nearly circular shape. Clear variations in the spectral shape of the X-ray emission across the object are dete…
The Physical Thickness of Stellar Disks to z ∼ 2
Heckman, Timothy M.; Snyder, Gregory F.; Simons, Raymond C. +2 more
In local disk galaxies such as our Milky Way, older stars generally inhabit a thicker disk than their younger counterparts. Two competing models have attempted to explain this result: one in which stars first form in thin disks that gradually thicken with time through dynamical heating, and one in which stars form in thick disks at early times and…
Characterizing a World Within the Hot-Neptune Desert: Transit Observations of LTT 9779 b with the Hubble Space Telescope/WFC3
Ward-Thompson, Derek; Stassun, Keivan G.; France, Kevin +27 more
We present an atmospheric analysis of LTT 9779 b, a rare planet situated in the hot-Neptune desert, that has been observed with Hubble Space Telescope (HST)/WFC3 with G102 and G141. The combined transmission spectrum, which covers 0.8-1.6 µm, shows a gradual increase in transit depth with wavelength. Our preferred atmospheric model shows evi…