Search Publications
A successful search for intervening 21 cm H I absorption in galaxies at 0.4 < z <1.0 with the Australian square kilometre array pathfinder (ASKAP)
Ellison, Sara L.; Koribalski, Bärbel S.; Lagos, Claudia del P. +6 more
We have used the Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope to search for intervening 21 cm neutral hydrogen (H I) absorption along the line of sight to 53 bright radio continuum sources. Our observations are sensitive to H I column densities typical of Damped Lyman Alpha absorbers (DLAs) in cool gas with an H I spin temp…
NuSTAR Discovery of a Compton-thick, Dust-obscured Galaxy: WISE J0825+3002
Tanimoto, Atsushi; Ueda, Yoshihiro; Kawamuro, Taiki +6 more
We report the discovery of a Compton-thick (CT), dust-obscured galaxy at z = 0.89, WISE J082501.48+300257.2 (WISE 0825+3002), observed by the Nuclear Spectroscopic Telescope Array. X-ray analysis with the XCLUMPY model revealed that hard X-ray luminosity in the rest-frame 2-10 keV band of WISE 0825+3002 is L X (2-10 keV) = {4.2}-1.…
Chandra Observations of NGC 7212: Large-scale Extended Hard X-Ray Emission
Elvis, Martin; Fabbiano, G.; Siemiginowska, A. +5 more
Recent observations of nearby Compton thick (CT) active galactic nuclei (AGNs) with Chandra have resolved hard (>3 keV) X-ray emission extending out from the central supermassive black hole to kiloparsec scales, challenging the long-held belief that the characteristic hard X-ray continuum and fluorescent Fe K lines originate in the inner ∼parse…
Search for 7Be in the outbursts of four recent novae
Bonifacio, P.; Hernanz, M.; Molaro, P. +3 more
Following the recent detection of 7Be II in the outburst spectra of classical novae, we report the search for this isotope in the outbursts of four recent bright novae by means of high-resolution Ultraviolet and Visual Echelle Spectrograph (UVES) observations. The 7Be II λλ313.0583, 313.1228 nm doublet resonance lines are det…
An Increase in Small-planet Occurrence with Metallicity for Late-type Dwarf Stars in the Kepler Field and Its Implications for Planet Formation
Cheng, Sihao; Schlaufman, Kevin C.; Lu, Cicero X.
While it is well-established that giant-planet occurrence rises rapidly with host star metallicity, it is not yet clear if small-planet occurrence around late-type dwarf stars depends on host star metallicity. Using the Kepler Data Release 25 planet candidate list and its completeness data products, we explore planet occurrence as a function of me…
TESS light curves of γ Cas stars
Nazé, Yaël; Rauw, Gregor; Pigulski, Andrzej
γ Cas stars constitute a subgroup of Be stars showing unusually hard and bright X-ray emission. In search for additional peculiarities, we analysed the TESS light curves of 15 γ Cas analogues. Their periodograms display broad frequency groups and/or narrow isolated peaks, often superimposed over red noise. The detected signals appear at low freque…
The orbital phase space of contracted dark matter haloes
Grand, Robert J. J.; Marinacci, Federico; Deason, Alis J. +4 more
We study the orbital phase space of dark matter (DM) haloes in the AURIGA suite of cosmological hydrodynamics simulations of Milky Way (MW) analogues. We characterize haloes by their spherical action distribution, $F\left(J_{{r}},L\right)$ , a function of the specific angular momentum, L, and the radial action, Jr, of the DM particles. …
Formation pathway for lonely stripped-envelope supernova progenitors: implications for Cassiopeia A
Sato, Toshiki; Podsiadlowski, Philipp; Mandel, Ilya +2 more
We explore a new scenario for producing stripped-envelope supernova progenitors. In our scenario, the stripped-envelope supernova is the second supernova of the binary, in which the envelope of the secondary was removed during its red supergiant phase by the impact of the first supernova. Through 2D hydrodynamical simulations, we find that ∼50-90 …
Efficient Methanol Production on the Dark Side of a Prestellar Core
Bizzocchi, Luca; Caselli, Paola; Rosolowsky, Erik +23 more
We present Atacama Large Millimeter/submillimeter Array maps of the starless molecular cloud core Ophiuchus/H-MM1 in the lines of deuterated ammonia (ortho- ${\mathrm{NH}}_{2}{\rm{D}}$ ), methanol ( ${\mathrm{CH}}_{3}\mathrm{OH}$ ), and sulfur monoxide (SO). The dense core is seen in ${\mathrm{NH}}_{2}{\rm{D}}$ emission, whereas the ${\mathrm{CH}}…
A catalogue of over 10 million variable source candidates in ZTF Data Release 1
Gal-Yam, Avishay; Ofek, Eran O.; Masci, Frank +4 more
Variable sources probe a wide range of astrophysical phenomena. We present a catalogue of over 10 million variable source candidates found in Data Release 1 (DR1) of the Zwicky Transient Facility (ZTF). We perform a periodicity search up to a frequency of 160 d-1, and we classify the light curves into erratic and smooth variables. We al…