Search Publications
Modeling the Hydrological Cycle in the Atmosphere of Mars: Influence of a Bimodal Size Distribution of Aerosol Nucleation Particles
Medvedev, Alexander S.; Fedorova, Anna A.; Hartogh, Paul +3 more
We present a new implementation of the hydrological cycle scheme into a general circulation model of the Martian atmosphere. The model includes a semi-Lagrangian transport scheme for water vapor and ice and accounts for microphysics of phase transitions between them. The hydrological scheme includes processes of saturation, nucleation, particle gr…
Downsizing of star formation measured from the clustered infrared background correlated with quasars
Crichton, Devin; Mandelbaum, Rachel; Zakamska, Nadia L. +2 more
Powerful quasars can be seen out to large distances. As they reside in massive dark matter haloes, they provide a useful tracer of large-scale structure. We stack Herschel-SPIRE images at 250, 350, and 500 µm at the location of 11 235 quasars in 10 redshift bins spanning 0.5 ≤ z ≤ 3.5. The unresolved dust emission of the quasar and its host …
On the multiplicity of ALMA Compact Array counterparts of far-infrared bright quasars
Pérez-Fournon, I.; Wang, L.; Hatziminaoglou, E. +5 more
We present ALMA Atacama Compact Array (ACA) 870 µm continuum maps of 28 infrared-bright SDSS quasars with Herschel/SPIRE detections at redshifts 2-4, the largest such sample ever observed with ALMA. The ACA detections are centred on the SDSS coordinates to within 1 ″ for about 80 per cent of the sample. Larger offsets indicate that the far-i…
Toward the ICRF3: Astrometric Comparison of the USNO 2016A VLBI Solution with ICRF2 and Gaia DR1
Dorland, Bryan N.; Makarov, Valeri V.; Johnson, Megan C. +2 more
The VLBI USNO 2016A (U16A) solution is part of a work-in-progress effort by USNO toward the preparation of the ICRF3. Most of the astrometric improvement with respect to the ICRF2 is due to the re-observation of the VCS sources. Our objective in this paper is to assess U16A’s astrometry. A comparison with ICRF2 shows statistically significant offs…
Color gradients reflect an inside-out growth in early-type galaxies of the cluster MACS J1206.2-0847
Ziegler, B.; Verdugo, M.; Kuchner, U. +1 more
Aims: Color gradients of galaxies are a powerful tool for resolving the variations of stellar populations within galaxies. We use this approach to explore the evolution of early-type galaxies in the core of the massive galaxy cluster MACS J1206.2-0847 at z = 0.44.
Methods: We used imaging data in 12 filters (covering a wavelength range f…
Don’t Blink: Constraining the Circumstellar Environment of the Interacting Type Ia Supernova 2015cp
Smith, M.; Filippenko, A. V.; Nugent, P. E. +12 more
Despite their cosmological utility, the progenitors of Type Ia supernovae (SNe Ia) are still unknown, with many efforts focused on whether accretion from a nondegenerate companion can grow a carbon-oxygen white dwarf to near the Chandrasekhar mass. The association of SNe Ia resembling SN 1991T (“91T-like”) with circumstellar interaction may be evi…
The Spread of Metals into the Low-redshift Intergalactic Medium
Danforth, Charles W.; Stocke, John T.; Keeney, Brian A. +1 more
We investigate the association between galaxies and metal-enriched and metal-deficient absorbers in the local universe (z < 0.16) using a large compilation of far-ultraviolet spectra of bright active galactic nuclei targets observed with the Cosmic Origins Spectrograph aboard the Hubble Space Telescope. In this homogeneous sample of 18 O VI det…
Is the Young Star RZ Piscium Consuming Its Own (Planetary) Offspring?
Kastner, J. H.; Punzi, K. M.; Melis, C. +4 more
The erratically variable star RZ Piscium (RZ Psc) displays extreme optical dropout events and strikingly large excess infrared emission. To ascertain the evolutionary status of this intriguing star, we obtained observations of RZ Psc with the European Space Agency’s X-ray Multi-Mirror Mission (XMM-Newton), as well as high-resolution optical spectr…
Spectral evolution of the supergiant HMXB IGR J16320-4751 along its orbit using XMM-Newton
García, Federico; Fogantini, Federico A.; Chaty, Sylvain +1 more
Context. The INTEGRAL satellite has revealed a previously hidden population of absorbed high-mass X-ray binaries (HMXBs) hosting supergiant stars. Among them, IGR J16320-4751 is a classical system intrinsically obscured by its environment, with a column density of ∼1023 cm-2, more than an order of magnitude higher than the in…
e-ASTROGAM mission: a major step forward for gamma-ray polarimetry
Laurent, Philippe; Hanlon, Lorraine; Gouiffès, Christian +5 more
e-ASTROGAM is a gamma-ray space mission proposed for the fifth medium-size mission (M5) of the European Space Agency. It is dedicated to the study of the nonthermal universe in the photon energy range from ∼0.15 MeV to 3 GeV with unprecedented sensitivity and angular and energy resolution, together with a ground-breaking capability for gamma-ray p…