Search Publications
Water vapor toward starless cores: The Herschel view
de Graauw, Th.; Liseau, R.; Braine, J. +63 more
Aims: Previous studies by the satellites SWAS and Odin provided stringent upper limits on the gas phase water abundance of dark clouds (x(H2O) < 7 × 10-9). We investigate the chemistry of water vapor in starless cores beyond the previous upper limits using the highly improved angular resolution and sensitivity of Hers…
The Herschel Virgo Cluster Survey. V. Star-forming dwarf galaxies - dust in metal-poor environments
Bomans, D. J.; Bianchi, S.; Fritz, J. +27 more
We present the dust properties of a small sample of Virgo cluster dwarf galaxies drawn from the science demonstration phase data set of the Herschel Virgo Cluster Survey. These galaxies have low metallicities (7.8 < 12 + log(O/H) < 8.3) and star-formation rates ≲10-1 M⊙ yr-1. We measure the spectral energy di…
Simulating the density and thermal structure of the middle atmosphere (∼80-130 km) of Mars using the MGCM-MTGCM: A comparison with MEX/SPICAM observations
Smith, M. D.; Forget, F.; Montmessin, F. +4 more
The objective of this work is to advance the understanding of the structure and dynamics of the middle altitude region of the martian atmosphere. While numerous advancements have been made in the level of scientific understanding of Mars's upper and lower atmospheres over the past several decades, insight into the mechanisms of the middle atmosphe…
Constraining the Outburst Properties of the SMBH in Fornax A Through X-ray, Infrared, and Radio Observations
Jones, Christine; Ashby, Matthew L. N.; Kraft, Ralph +3 more
Combined Spitzer, Chandra, XMM-Newton, and VLA observations of the giant radio galaxy NGC 1316 (Fornax A) show a radio jet and X-ray cavities from active galactic nucleus (AGN) outbursts most likely triggered by a merger with a late-type galaxy at least 0.4 Gyr ago. We detect a weak nucleus with a spectral energy distribution typical of a low-lumi…
Total electron content in the Mars ionosphere: Temporal studies and dependence on solar EUV flux
Withers, Paul; Safaeinili, Ali; Brain, David A. +3 more
Total electron content (TEC) derived from radar signal distortions is a useful tool in probing the ionosphere of Mars. We consider 26 months of data from the subsurface mode of the Mars Express MARSIS instrument and confirm that the TEC dependence on solar zenith angle (SZA) approximately matches Chapman theory. After detrending this dependence, w…
A Wide-Field Survey of the Orion Nebula Cluster in the Near-Infrared
Robberto, M.; Scandariato, G.; Da Rio, N. +4 more
We present J, H, and K S photometry of the Orion Nebula Cluster (ONC) obtained at the CTIO/Blanco 4 m telescope at Cerro Tololo with the Infrared Side Port Imager camera. From the observations we have assembled a catalog of about ~7800 sources distributed over an area of approximately 30' × 40', the largest of any survey deeper than th…
The Size, Density, and Formation of the Orcus-Vanth System in the Kuiper Belt
Ragozzine, D.; Brown, M. E.; Stansberry, J. +1 more
The Kuiper Belt object (KBO) Orcus and its satellite Vanth form an unusual system in the Kuiper Belt. While most large KBOs have small satellites in circular orbits and smaller KBOs and their satellites tend to be much closer in size, Orcus sits in between these two regimes. Orcus is among the largest objects known in the Kuiper Belt, but the rela…
Witnessing the Key Early Phase of Quasar Evolution: An Obscured Active Galactic Nucleus Pair in the Interacting Galaxy IRAS 20210+1121
Maiolino, Roberto; Nicastro, Fabrizio; Fiore, Fabrizio +6 more
We report the discovery of an active galactic nucleus (AGN) pair in the interacting galaxy system IRAS 20210+1121 at z = 0.056. An XMM-Newton observation reveals the presence of an obscured (N H ~ 5 × 1023 cm-2), Seyfert-like (L 2-10 keV = 4.7 × 1042 erg s-1) nucleus in the northern…
Constraining the low-mass end of the initial mass function with gravitational lensing
Courbin, Frédéric; Saha, Prasenjit; Ferreras, Ignacio +2 more
The low-mass end of the stellar initial mass function (IMF) is constrained by focusing on the baryon-dominated central regions of strong lensing galaxies. We study in this Letter the Einstein Cross (Q2237+0305), a z = 0.04 barred galaxy whose bulge acts as lens on a background quasar. The positions of the four quasar images constrain the surface m…
Modelling the light variability of the Ap star ɛ Ursae Majoris
Shulyak, D.; Kochukhov, O.; Krtička, J. +2 more
Aims: We simulate the light variability of the Ap star ɛ UMa using the observed surface distributions of Fe, Cr, Ca, Mn, Mg, Sr, and Ti obtained with the help of the Doppler imaging technique.
Methods: Using all photometric data available, we specified light variations of ɛ UMa modulated by its rotation from far UV to IR. We employed the…