Search Publications
The nearby interstellar medium toward α Leo. UV observations and modeling of a warm cloud within hot gas
Jenkins, Edward B.; Gry, Cecile
Aims: Our aim is to characterize the conditions in the nearest interstellar cloud.
Methods: We analyze interstellar absorption features in the full UV spectrum of the nearby (d = 24 pc) B8 IVn star
Chemical abundances of two extragalactic young massive clusters
Hernandez, Svea; Kaper, Lex; Larsen, Søren +2 more
Aims: We use integrated-light spectroscopic observations to measure metallicities and chemical abundances for two extragalactic young massive star clusters (NGC 1313-379 and NGC 1705-1). The spectra were obtained with the X-shooter spectrograph on the ESO Very Large Telescope.
Methods: We compute synthetic integrated-light spectra, based…
Calibration of the photometric G passband for Gaia Data Release 1
Maíz Apellániz, J.
Context. On September 2016 the first data from Gaia were released (DR1). The first release included photometry for over 109 sources in the very broad G system.
Aims: The aims here are to test the correspondence between G magnitudes in DR1 and the synthetic equivalents derived using spectral energy distributions from observed and mo…
Extended Gamma-Ray Emission from the G25.0+0.0 Region: A Star-forming Region Powered by the Newly Found OB Association?
Funk, S.; Uchiyama, Y.; Katsuta, J.
We report a study of extended γ-ray emission with the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope, which is likely to be the second case of a γ-ray detection from a star-forming region (SFR) in our Galaxy. The LAT source is located in the G25 region, 1.°7 × 2.°1 around (l, b) = (25.°0, 0.°0). The γ-ray emission is found…
Inflowing gas onto a compact obscured nucleus in Arp 299A. Herschel spectroscopic studies of H2O and OH
González-Alfonso, E.; Aalto, S.; Fischer, J. +1 more
Aims: We probe the physical conditions in the core of Arp 299A and try to put constraints on the nature of its nuclear power source.
Methods: We used Herschel Space Observatory far-infrared and submillimeter observations of H2O and OH rotational lines in Arp 299A to create a multi-component model of the galaxy. In doing this, …
Young LMC clusters: the role of red supergiants and multiple stellar populations in their integrated light and CMDs
Beasley, Michael A.; Vazdekis, Alexandre; Cerviño, Miguel +3 more
The optical integrated spectra of three Large Magellanic Cloud young stellar clusters (NGC 1984, NGC 1994 and NGC 2011) exhibit concave continua and prominent molecular bands which deviate significantly from the predictions of single stellar population (SSP) models. In order to understand the appearance of these spectra, we create a set of young s…
On the discrepancy between asteroseismic and Gaia DR1 TGAS parallaxes
Gontcharov, George A.; Mosenkov, Aleksandr V.
Recently, a deviation of the Gaia Tycho-Gaia Astrometric Solution (TGAS) parallaxes from the asteroseismic ones for giants was found. We show that for parallaxes ϖ < 1.5 mas it can be explained by a selection effect in favour of bright and luminous giants in the Tycho-2 and TGAS catalogues. Another explanation of this deviation seems to be vali…
Modelling the observed stellar mass function and its radial variation in galactic globular clusters
Vesperini, Enrico; Dalessandro, Emanuele; Ferraro, Francesco R. +3 more
We measure how the slope α of the stellar mass function (MF) changes as a function of clustercentric distance r in five Galactic globular clusters and compare α(r) to predictions from direct N-body star cluster simulations. Theoretical studies predict that α(r) (which traces the degree of mass segregation in a cluster) should steepen with time as …
The Warm Circumgalactic Medium: 105-6 K Gas Associated with a Single Galaxy Halo or with an Entire Group of Galaxies?
Danforth, Charles W.; Stocke, John T.; Keeney, Brian A. +3 more
In preparation for a Hubble Space Telescope (HST) observing project using the Cosmic Origins Spectrograph (COS), the positions of all AGN targets having high-S/N far-UV G130M spectra were cross-correlated with a large catalog of low-redshift galaxy groups homogenously selected from the spectroscopic sample of the Sloan Digital Sky Survey (SDSS). S…
Ultra low frequency waves at Venus: Observations by the Venus Express spacecraft
Fränz, M.; Zhang, T. L.; Dubinin, E. +2 more
The generation of waves with low frequencies (below 100 mHz) has been observed in the environment of most bodies in the solar system and well studied at Earth. These waves can be generated either upstream of the body in the solar wind by ionization of planetary exospheres or ions reflected from a bow shock or in the magnetosheath closer to the mag…