Search Publications
VLA/JVLA monitoring of bright northern radio sources
López-Caniego, M.; Partridge, B.; Myers, S. +3 more
We report multiple epoch VLA/JVLA observations of 89 northern hemisphere sources, most with 37 GHz flux density >1 Jy, observed at 4.8, 8.5, 33.5, and 43.3 GHz. The high frequency selection leads to a predominantly flat spectrum sample, with 85% of our sources being in the Planck Early Release Compact Source Catalog (ERCSC). These observations …
Submillimeter observations of IRAS and WISE debris disk candidates
Dowell, C. D.; De Rosa, R. J.; McCarthy, D. +7 more
A set of six debris disk candidates identified with IRAS or WISE excesses were observed at either 350 µm or 450 µm with the Caltech Submillimeter Observatory. Five of the targets - HIP 51658, HIP 68160, HIP 73512, HIP 76375, and HIP 112460 - have among the largest measured excess emission from cold dust from IRAS in the 25-100 µm…
Fluctuations of the intergalactic ionization field at redshift z ~ 2
Reimers, D.; Hagen, H. -J.; Levshakov, S. A. +2 more
Aims: To probe the spectral energy distribution (SED) of the ionizing background radiation at z ≲ 2 and to specify the sources contributing to the intergalactic radiation field.
Methods: The spectrum of a bright quasar
WR 138: new results from X-ray and optical spectroscopy
Nazé, Y.; Rauw, G.; De Becker, M. +2 more
Context. Massive-binary evolution models predict that some systems will go through an evolutionary phase where the original primary has become a supernova and left a compact object behind that then orbits a Wolf-Rayet (WR) star. WR 138 is an X-ray bright WR star that has been described as a triple system, including a compact companion in a short-p…
The multiplicity of φ Phe revisited
Pourbaix, D.; Chini, R.; Boffin, H. M. J. +1 more
Aims: The chemically peculiar B star φ Phe was, until very recently, considered to be a triple system, even though the data were not conclusive and the orbits rather uncertain. Very recent results provided a revised orbit, different from the then available astrometric Hipparcos orbit.
Methods: Additional spectroscopic data obtained with …
Empirical determination of the temperature stratification in the photosphere of the quiet Sun
Faurobert, M.; Ricort, G.; Aime, C.
Context. Detailed realistic 3D simulations of the photosphere of the Sun are now available, but 1D models of the average quiet-Sun photosphere are still widely used, in particular for spectro-polarimetric inversions.
Aims: Here we present an empirical determination of the average radiation temperature variations as a function of the geometric…
Physical properties of outflows. Comparing CO- and H2O-based parameters in Class 0 sources
Liseau, R.; Melnick, G.; Bjerkeli, P. +4 more
Context. The observed physical properties of outflows from low-mass sources put constraints on possible ejection mechanisms. Historically, these quantities have been derived from CO using ground-based observations. It is, therefore, important to investigate whether parameters such as momentum rate (thrust) and mechanical luminosity (power) are the…
Rotational non-LTE in HCN in the thermosphere of Titan: Implications for the radiative cooling
Hartogh, P.; Rezac, L.; Kutepov, A. A. +2 more
Context. The thermal structure of Titan's thermosphere is determined by the balance between several heating and cooling processes. These processes must be accurately modeled to correctly interpret the available measurements and enhance our understanding of the formation and evolution of this atmosphere. One of the most important thermospheric cool…
A BeppoSAX and XMM-Newton spectral study of 4U 1735-44
Santangelo, A.; Mück, B.; Piraino, S.
Context. Low-mass X-ray binary systems consist of a neutron star and a main-sequence companion star. The compact object accretes matter via Roche-lobe overflow, which leads to an accretion disk. In addition to a broad-band continuum emission of a thermal component and a Comptonization part, evidence for a broad iron Kα line is found in …
Studying the non-thermal lobes of IRAS 16547-4247 through a multi-wavelength approach
Iwasawa, K.; Paredes, J. M.; Munar-Adrover, P. +1 more
In recent years, massive protostars have turned out to be a possible population of high-energy emitters. Among the best candidates is IRAS 16547-4247, a protostar that presents a powerful outflow with clear signatures of interaction with its environment. This source has been revealed to be a potential high-energy source because it displays non-the…