Search Publications
Detailed Atmosphere Modeling for the Neutron Star 1E1207.4-5209: Evidence of Oxygen/Neon Atmosphere
Hailey, Charles J.; Mori, Kaya
We present a comprehensive investigation of the two broad absorption features observed in the X-ray spectrum of the neutron star 1E1207.4-5209 based on a recent analysis of the 260 ks XMM-Newton data by Mori et al. Expanding on earlier work by Hailey & Mori, we have examined all previously proposed atmospheric models for 1E1207.4-5209. Using o…
Integral field spectroscopy of Hα emission in cooling flow cluster cores: disturbing the molecular gas reservoir
Swinbank, A. M.; Edge, A. C.; Wilman, R. J.
We present optical integral field spectroscopy of the Hα-luminous (>1042ergs-1) central cluster galaxies in the cores of the cooling flow clusters A1664, A1835, A2204 and Zw8193. From the [NII]+Hα complex in these moderate resolution (70-150kms-1) spectra we derive 2D views of the distribution and kinematics of …
XMM-Newton View of PKS 2155-304: Hardness Ratio and Cross-Correlation Analysis of EPIC pn Observations
Maraschi, L.; Treves, A.; Zhang, Y. H. +2 more
With currently available XMM-Newton EPIC pn observations spanned over about 3 yr, we present a detailed spectral and temporal variability of the 0.2-10 keV X-ray emission from the X-ray-bright BL Lac object PKS 2155-304. The spectral variability is examined with a model-independent hardness ratio method. We find that the spectral evolution of the …
Estimating Black Hole Masses of AGNs using Ultraviolet Emission Line Properties
Wang, Ran; Wu, Xue-Bing; Kong, Min-Zhi +1 more
Based on measured broad line region sizes in the reverberation-mapping AGN sample, two new empirical relations are introduced to estimate the central black hole masses of radio-loud high-redshift (z>0.5) AGNs. First, using the archival IUE/HST spectroscopy data at UV band for the reverberation-mapping objects, we obtained two new empirical rela…
Low-Redshift Intergalactic Absorption Lines in the Spectrum of HE 0226-4110
Savage, B. D.; Wakker, B. P.; Sembach, K. R. +2 more
We present an analysis of the FUSE and HST STIS E140M spectra of HE 0226-4110 (z=0.495). We detect 56 Lyman absorbers and five O VI absorbers. The number of intervening O VI systems per unit redshift with Wλ>~50 mÅ is dN(O VI)/dz~11. The O VI systems unambiguously trace hot gas only in one case. For the four other O VI systems, photo…
Direct Measurement of the Size of 2003 UB313 from the Hubble Space Telescope
Brown, M. E.; Schaller, E. L.; Roe, H. G. +2 more
We have used the Hubble Space Telescope to directly measure the angular size of the large Kuiper Belt object 2003 UB313. By carefully calibrating the point-spread function of a nearby field star, we measure the size of 2003 UB313 to be 34.3+/-1.4 mas, corresponding to a diameter of 2400+/-100 km or a size ~5% larger than Pluto. The V-band geometri…
A posteriori detection of the planetary transit of HD 189733 b in the Hipparcos photometry
Hébrard, G.; Lecavelier Des Etangs, A.
Context: Aims: Using observations performed at the Haute-Provence Observatory, the detection of a 2.2-day orbital period extra-solar planet that transits the disk of its parent star, HD 189733, has been recently reported. We searched in the Hipparcos photometry Catalogue for possible detections of those transits. Methods: Statistic studies were pe…
Cluster observations in the magnetosheath - Part 1: Anisotropies of the wave vector distribution of the turbulence at electron scales
Maksimovic, M.; Trávníček, P.; Cornilleau-Wehrlin, N. +5 more
We analyse the power spectral density δB2 and δE2 of the magnetic and electric fluctuations measured by Cluster 1 (Rumba) in the magnetosheath during 23 h, on four different days. The frequency range of the STAFF Spectral Analyser (f=8 Hz to 4 kHz) extends from about the lower hybrid frequency, i.e. the electromagnetic (e.m.)…
GALEX Observations of ``Passive Spirals'' in the Cluster Cl 0024+17: Clues to the Formation of S0 Galaxies
Smith, Graham P.; Treu, Tommaso; Ellis, Richard S. +4 more
We present new results from deep GALEX UV imaging of the cluster Cl 0024+17 at z~0.4. Rest-frame far-UV emission is detected from a large fraction of so-called passive spiral galaxies-a significant population that exhibits spiral morphology with little or no spectroscopic evidence of ongoing star formation. This population is thought to represent …
New members in the Upper Scorpius association from the UKIRT Infrared Deep Sky Survey Early Data Release†
Hambly, N. C.; Jameson, R. F.; Lodieu, N.
We present the results of a 9.3-deg2 infrared (ZYJHK) survey in the Upper Scorpius association extracted from the UKIRT Infrared Deep Sky Survey (UKIDSS) Galactic Cluster Survey Early Data Release. We have selected a total of 112 candidates from the (Z-J, Z) colour-magnitude diagram over the Z= 12.5-20.5 magnitude range, corresponding t…