Search Publications
Redshifts in the Hubble Deep Field South
Sawicki, Marcin; Mallén-Ornelas, Gabriela
We present a catalog of 97 spectroscopic redshifts of z<1 galaxies in the Hubble Deep Field South (HDF-S) and its flanking fields (FFs). In the HDF-S proper we observed approximately half the galaxies brighter than I814(AB)=24 and obtained redshifts for 76% of them. Targets in our HDF-S sample were preselected to be at z<1 based o…
An intense and broad Fe Kalpha line observed in the X-ray luminous quasar Q 0056-363 with XMM-Newton
Porquet, D.; Reeves, J. N.
We present an XMM-Newton observation of the radio-quiet quasar
High-Resolution Continuum Imaging at 1.3 and 0.7 Centimeters of the W3 IRS 5 Region
Megeath, S. T.; Wilson, T. L.; Boboltz, D. A. +1 more
High-resolution images of the hypercompact H II (HC H II) regions in W3 IRS 5 taken with the Very Large Array (VLA) at 1.3 and 0.7 cm are presented. Four HC H II regions were detected with sufficient signal-to-noise ratios to allow the determination of relevant parameters, such as source position, size, and flux density. The sources are slightly e…
Imaging and Spectroscopy of Galaxies Associated with Two z~0.7 Damped Lyα Absorption Systems
White, Richard L.; Gregg, Michael D.; Lacy, Mark +3 more
We have identified galaxies near two quasars that are at the redshift of damped Lyα (DLA) systems in the UV spectra of the quasars. Both galaxies are actively forming stars. One galaxy has a luminosity close to the break in the local galaxy luminosity function, L*; the other is significantly fainter than L* and appears to be interacting with a nea…
XMM-Newton observation of PG 0844+349
Branduardi-Raymont, G.; Brinkmann, W.; Grupe, D. +1 more
In a ~ 20 ksec XMM-Newton observation the X-ray transient radio-quiet quasar PG 0844+349 was found in a historically high state compared to previous X-ray observations. The quasar showed a featureless spectrum with a strong soft excess over the extrapolation of a hard power law. Comptonization models or a broken power law with Gammasoft…
On the nature of Collinder 121: insights from the low-mass pre-main sequence
Naylor, Tim; Jeffries, R. D.; Burningham, Ben +1 more
We present a VI photometric catalogue towards the open cluster Cr 121. XMM-Newton and ROSAT data are used to discover a low-mass pre-main sequence (PMS) along this sightline. de Zeeuw et al. have identified Cr 121 as a moving group, using Hipparcos data, at a distance of 592 pc; we reject the scenario that these low-mass PMS stars are associated w…
Search for the Optical Counterpart of the Vela Pulsar X-Ray Nebula
Caraveo, P. A.; De Luca, A.; Zaggia, S. +4 more
Observations of the Vela pulsar region with the Chandra X-Ray Observatory have revealed the fine structure of its synchrotron pulsar-wind nebula (PWN), which showed an overall similarity with the Crab PWN. However, contrary to the Crab, no firm detection of the Vela PWN in optical has been reported yet. To search for the optical counterpart of the…
Chemical evolution of the M82 B fossil starburst
de Grijs, Richard; Gilmore, Gerry; Parmentier, Geneviève
M82 B is an old starburst site located in the eastern part of the M82 disc. We derive the distributions of age and metallicity of the star clusters located in this region of M82 by using theoretical evolutionary population synthesis models. Our analysis is based on the comparison of the BVIJ photometry obtained by de Grijs, O'Connel & Gallaghe…
Scientific objectives of the Beagle 2 lander
Pillinger, C. T.; Sims, M. R.; Wright, I. P.
Beagle 2 is the name given to the lander part of the ESA Mars Express mission (launch 2003). The main focus of Beagle 2 is to establish whether there is convincing evidence for past life on Mars, or to assess if the conditions were ever suitable. Beagle 2 also plans a globally responsive test to see if there is any present-day biological activity …
Is Praesepe really different from the coeval Hyades cluster? The XMM-Newton view
Pallavicini, R.; Franciosini, E.; Randich, S.
The Praesepe open cluster represents a puzzle since it has about the same age as the Hyades, and only slightly different metallicity, yet previous ROSAT observations resulted in a detection rate of cluster sources significantly lower than for the Hyades. We present a new 50 ksec observation of Praesepe performed with the EPIC instrument on board X…