Search Publications
OVII and OVIII line emission in the diffuse soft X-ray background: heliospheric and galactic contributions
Ballet, J.; Lallement, R.; Acero, F. +2 more
Aims:We study the 0.57 keV (O VII triplet) and 0.65 keV (O VIII) diffuse emission generated by charge transfer collisions between solar wind (SW) oxygen ions and interstellar H and He neutral atoms in the inner Heliosphere. These lines which dominate the 0.3-1.0 keV energy interval are also produced by hot gas in the galactic halo (GH) and possibl…
New scaling relations in cluster radio haloes and the re-acceleration model
Brunetti, G.; Setti, G.; Cassano, R. +2 more
In this paper we derive new expected scaling relations for clusters with giant radio haloes in the framework of the re-acceleration scenario in a simplified, but physically motivated, form, namely: radio power (PR) versus size of the radio emitting region (RH), and PR versus total cluster mass (MH) conta…
A Very Bright, Highly Magnified Lyman Break Galaxy at z = 3.07
Kneib, J. -P.; Smith, G. P.; Smail, Ian +8 more
Using Hubble Space Telescope imaging and Keck spectroscopy, we report the discovery of a very bright, highly magnified (~30 times) Lyman break galaxy (LBG) at z=3.07 in the field of the massive z=0.33 cluster MACS J2135.2-0102. The system comprises two high surface brightness arcs with a maximum extent of 3", bracketing a central object that we id…
Central kiloparsec of Seyfert and inactive host galaxies: a comparison of two-dimensional stellar and gaseous kinematics
Emsellem, Eric; Nagar, Neil M.; Mundell, Carole G. +1 more
We investigate the properties of the two-dimensional distribution and kinematics of ionized gas and stars in the central kiloparsec of a matched sample of nearby active (Seyfert) and inactive galaxies, using the SAURON integral field unit on the William Herschel Telescope. The ionized gas distributions show a range of low-excitation regions, such …
Cassini States with Dissipation: Why Obliquity Tides Cannot Inflate Hot Jupiters
Fabrycky, Daniel C.; Johnson, Eric T.; Goodman, Jeremy
Some short-period exoplanets (``hot Jupiters'') are observed by their transits to have anomalously large radii. It has been suggested that these planets are in a resonance involving persistent misalignment and synchronous precession of their spin and orbital angular momenta (a Cassini state) and that the attendant tidal heating inflates the planet…
Suzaku Observations of the Local and Distant Hot ISM
Hamaguchi, Kenji; Ishida, Manabu; Kilbourne, Caroline A. +18 more
Suzaku observed the molecular cloud MBM 12 and a blank field less than 3° away to separate the local and distant components of the diffuse soft X-ray background. Towards MBM 12, a local (D ≲ 275 pc) O VII emission line was clearly detected with an intensity of 3.5 photons cm-2 s-1 sr-1 (or line units, LU), and the …
Collimation, Proper Motions, and Physical Conditions in the HH 30 Jet from Hubble Space Telescope Slitless Spectroscopy
Hartigan, Patrick; Morse, Jon
We present STIS spectral images of the HH 30 stellar jet taken through a wide slit over two epochs. The jet is unresolved spectrally, so the observations produce emission-line images for each line in the spectrum. This rich data set shows how physical conditions in the jet vary with distance and time, produces precise proper motions of knots withi…
An updated survey of globular clusters in M 31. II. Newly discovered bright and remote clusters
Bellazzini, M.; Galleti, S.; Federici, L. +2 more
Aims:We present the first results of a large spectroscopic survey of candidate globular clusters located in the extreme outskirts of the nearby M 31 galaxy. The survey is aimed at ascertaining the nature of the selected candidates to increase the sample of confirmed M 31 clusters lying more that 2° away from the center of the galaxy.
Methods: …
The escape of Lyman photons from a young starburst: the case of Haro11†
Hayes, Matthew; Östlin, Göran; Leitherer, Claus +5 more
Lyman α (Lyα) is one of the dominant tools used to probe the star-forming galaxy population at high redshift (z). However, astrophysical interpretations of data drawn from Lyα alone hinge on the Lyα escape fraction which, due to the complex radiative transport, may vary greatly. Here, we map the Lyα emission from the local luminous blue compact ga…
SWSextantis stars: the dominant population of cataclysmic variables with orbital periods between 3 and 4h
Gänsicke, B. T.; Allende Prieto, C.; Hagen, H. -J. +15 more
We present time-series optical photometry of five new cataclysmic variables (CVs) identified by the Hamburg Quasar Survey (HQS). The deep eclipses observed in HS 0129+2933 (= TT Tri), HS 0220+0603 and HS 0455+8315 provided very accurate orbital periods of 3.35129827(65), 3.58098501(34) and 3.56937674(26) h, respectively. HS 0805+3822 shows grazing…