Search Publications
Search for associations containing young stars (SACY). VII. New stellar and substellar candidate members in the young associations
Bayo, A.; Montes, D.; Sterzik, M. F. +5 more
Context. The young associations offer us one of the best opportunities to study the properties of young stellar and substellar objects and to directly image planets thanks to their proximity (<200 pc) and age (≈5-150 Myr). However, many previous works have been limited to identifying the brighter, more active members (≈1 M⊙) owing to…
Constraints on dark-matter properties from large-scale structure
Kunz, Martin; Nesseris, Savvas; Sawicki, Ignacy
We use large-scale cosmological observations to place constraints on the dark-matter pressure, sound speed and viscosity and infer a limit on the mass of warm-dark-matter particles. Measurements of the cosmic microwave background anisotropies constrain the equation of state and sound speed of the dark matter (DM) at last scattering at the per mill…
Nature of the Soft ULX in NGC 247: Super-Eddington Outflow and Transition between the Supersoft and Soft Ultraluminous Regimes
Tao, Lian; Feng, Hua; Grisé, Fabien +1 more
We report on XMM-Newton/Chandra/Swift/Hubble Space Telescope observations of the ultraluminous X-ray source (ULX) in NGC 247, which is found to make transitions between the supersoft ultraluminous (SSUL) regime with a spectrum dominated by a cool (∼0.1 keV) blackbody component and the soft ultraluminous (SUL) regime with comparable luminosities sh…
A HIFI view on circumstellar H2O in M-type AGB stars: radiative transfer, velocity profiles, and H2O line cooling
Olofsson, H.; Justtanont, K.; De Beck, E. +4 more
Aims: We aim to constrain the temperature and velocity structures, and H2O abundances in the winds of a sample of M-type asymptotic giant branch (AGB) stars. We further aim to determine the effect of H2O line cooling on the energy balance in the inner circumstellar envelope.
Methods: We use two radiative-transfer co…
Pre-inflationary relics in the CMB?
Gruppuso, A.; Mandolesi, N.; Natoli, P. +2 more
String Theory and Supergravity allow, in principle, to follow the transition of the inflaton from pre-inflationary fast roll to slow roll. This introduces an infrared depression in the primordial power spectrum that might have left an imprint in the CMB anisotropy, if it occurred at accessible wavelengths. We model the effect extending Λ CDM with …
Spatially resolved integral field spectroscopy of the ionized gas in IZw18
Kunth, D.; Durret, F.; Brinchmann, J. +6 more
We present a detailed 2D study of the ionized ionized interstellar medium (ISM) of IZw18 using new Potsdam Multi-Aperture Spectrophotometer-integral field unit (PMAS-IFU) optical observations. IZw18 is a high-ionization galaxy which is among the most metal-poor starbursts in the local Universe. This makes IZw18 a local benchmark for understanding …
The selective effect of environment on the atomic and molecular gas-to-dust ratio of nearby galaxies in the Herschel Reference Survey
Ciesla, L.; Boquien, M.; Baes, M. +10 more
We combine dust, atomic (H I) and molecular (H2) hydrogen mass measurements for 176 galaxies in the Herschel Reference Survey to investigate the effect of environment on the gas-to-dust mass (Mgas/Mdust) ratio of nearby galaxies. We find that, at fixed stellar mass, the average Mgas/Mdust rati…
Parallax and masses of α Centauri revisited
Boffin, Henri M. J.; Pourbaix, Dimitri
Context. Despite the thorough work of van Leeuwen, the parallax of α Centauri is still far from being carved in stone. Any derivation of the individual masses is therefore uncertain, if not questionable. And yet, that does not prevent this system from being used for calibration purpose in several studies.
Aims: We aim for more accurate model-…
A statistical study of EMIC waves observed by Cluster: 2. Associated plasma conditions
André, M.; Klecker, B.; Kistler, L. M. +6 more
This is the second in a pair of papers discussing a statistical study of electromagnetic ion cyclotron (EMIC) waves detected during 10 years (2001-2010) of Cluster observations. In the first paper, an analysis of EMIC wave properties (i.e., wave power, polarization, normal angle, and wave propagation angle) is presented in both the magnetic latitu…
What Is Controlling the Fragmentation in the Infrared Dark Cloud G14.225-0.506?: Different Levels of Fragmentation in Twin Hubs.
Zhang, Qizhou; Palau, Aina; Pillai, Thushara +7 more
We present observations of the 1.3 mm continuum emission toward hub-N and hub-S of the infrared dark cloud G14.225-0.506 carried out with the Submillimeter Array, together with observations of the dust emission at 870 and 350 µm obtained with APEX and CSO telescopes. The large-scale dust emission of both hubs consists of a single peaked clum…