Search Publications
The Optical/Near-Infrared Counterpart of the INTEGRAL Obscured Source IGR J16318-4848: An sgB[e] in a High-Mass X-Ray Binary?
Filliatre, P.; Chaty, S.
The X-ray source IGR J16318-4848 was the first source discovered by INTEGRAL on 2003 January 29. The high-energy spectrum exhibits such a high column density that the source is undetectable in X-rays below 2 keV. On 2003 February 23-25, we triggered our Target of Opportunity (ToO) program using the EMMI and SOFI instruments on the New Technology T…
GRAPES, Grism Spectroscopy of the Hubble Ultra Deep Field: Description and Data Reduction
Cimatti, A.; Daddi, E.; Panagia, N. +19 more
We present deep unbiased spectroscopy of the Hubble Ultra Deep Field (UDF) carried out using the slitless grism spectroscopy mode of the Advanced Camera for Surveys on the Hubble Space Telescope (HST). The Grism ACS Program for Extragalactic Science (GRAPES) achieves continuum detection as faint as zAB=27.2 using 40 orbits (9.2×104…
Ultra-High-Precision Velocity Measurements of Oscillations in α Centauri A
Butler, R. Paul; Bedding, Timothy R.; Marcy, Geoffrey W. +5 more
We have made differential radial velocity measurements of the star α Centauri A using two spectrographs, the UV-Visual Echelle Spectrograph (UVES) and the University College London Echelle Spectrograph (UCLES), both with iodine absorption cells for wavelength referencing. Stellar oscillations are clearly visible in the time series. After removing …
Flares from small to large: X-ray spectroscopy of Proxima Centauri with XMM-Newton
Audard, M.; Güdel, M.; Linsky, J. L. +2 more
We report results from a comprehensive study of the nearby M dwarf Proxima Centauri with the XMM-Newton satellite, using simultaneously its X-ray detectors and the Optical Monitor with its U band filter. We find strongly variable coronal X-ray emission, with flares ranging over a factor of 100 in peak flux. The low-level emission is found to be co…
Cluster observations of continuous reconnection at the magnetopause under steady interplanetary magnetic field conditions
Balogh, A.; Klecker, B.; Rème, H. +9 more
Available from http://www.copernicus.org/site/EGU/annales/22/7/2355.htm?FrameEngine=false;
Observing the Formation of the Hubble Sequence in the Great Observatories Origins Deep Survey
Grogin, Norman A.; Lucas, Ray A.; Ravindranath, Swara +6 more
Understanding the physical formation of the Hubble sequence remains one of the most important unsolved astrophysical problems. Searches for protodisks and proto-elliptical galaxies can now be effectively done using deep wide-field Hubble Space Telescope images taken with the new Advanced Camera for Surveys. Through an analysis of the concentration…
The Fluctuating Intergalactic Radiation Field at Redshifts z = 2.3-2.9 from He II and H I Absorption toward HE 2347-4342
Shull, J. Michael; Kriss, Gerard A.; Tumlinson, Jason +2 more
We provide an in-depth analysis of the He II and H I absorption in the intergalactic medium (IGM) at redshifts z=2.3-2.9 toward HE 2347-4342, using spectra from the Far Ultraviolet Spectroscopic Explorer and the Ultraviolet-Visual Echelle Spectrograph on the Very Large Telescope. Following up on our earlier study, we focus here on two major topics…
Indications of a Large Fraction of Spectroscopic Binaries among Nuclei of Planetary Nebulae
Bond, Howard E.; De Marco, Orsola; Harmer, Dianne +1 more
Previous work indicates that about 10% of planetary-nebula nuclei (PNNi) are photometrically variable short-period binaries with periods of hours to a few days. These systems have most likely descended from common-envelope (CE) interactions in initially much wider binaries. Population-synthesis studies suggest that these very close pairs could be …
Study of the properties and spectral energy distributions of the Herbig AeBe stars HD 34282 and HD 141569
Rauer, H.; Schneider, J.; Eiroa, C. +21 more
We present a study of the stellar parameters, distances and spectral energy distributions (SEDs) of
Flux and energy modulation of redshifted iron emission in NGC 3516: implications for the black hole mass
Iwasawa, K.; Fabian, A. C.; Miniutti, G.
We report on the tentative detection of the modulation of a transient, redshifted Fe Kα emission feature in the X-ray spectrum of the Seyfert galaxy NGC 3516. The detection of the spectral feature at 6.1 keV, in addition to a stable 6.4-keV line, has been reported previously. We find, on reanalysing the XMM-Newton data, that the feature varies sys…