Search Publications
Host Dynamics and Origin of Palomar-Green QSOs
Lutz, D.; Genzel, R.; Sturm, E. +7 more
We present host galaxy velocity dispersions of 12 local (mainly Palomar-Green) QSOs measured directly from the stellar CO absorption features in the H band. The mean bulge dispersion of the QSOs in our sample is 186 km s-1 with a standard deviation of 24 km s-1. The measurement of the stellar dispersion in QSOs enables us to …
Hubble Space Telescope Parallaxes of AM CVn Stars and Astrophysical Consequences
Groot, P. J.; McArthur, B. E.; Benedict, G. F. +5 more
We present absolute parallaxes and relative proper motions for five AM CVn stars, which we obtained using the Fine Guidance Sensors on board the Hubble Space Telescope. Our parallax measurements translate into distances dAMCVn=606+135-93 pc, dHPLib=197+14-12 pc, dCRBoo=33…
The INTEGRAL Galactic bulge monitoring program: the first 1.5 years
Wijnands, R.; Mowlavi, N.; Kretschmar, P. +13 more
Aims:The Galactic bulge region is a rich host of variable high-energy point sources. Since 2005, February 17 we are monitoring the source activity in the Galactic bulge region regularly and frequently, i.e., about every three days, with the instruments onboard INTEGRAL. Thanks to the large field of view, the imaging capabilities and the sensitivit…
The Gemini Deep Deep Survey. VIII. When Did Early-Type Galaxies Form?
Glazebrook, Karl; McCarthy, Patrick J.; Yan, Haojing +13 more
We have used the Hubble Space Telescope's Advanced Camera for Surveys (Ford et al. 2003) to measure the cumulative mass density in morphologically selected early-type galaxies over the redshift range 0.8<z<1.7. Our imaging data set covers four well-separated sight lines and is roughly intermediate (in terms of both depth and area) between th…
Lyα emission in high-redshift galaxies
Noll, S.; Heidt, J.; Appenzeller, I. +4 more
Context: A significant fraction of the high-redshift galaxies show strong Lyα emission lines. For redshifts z > 5, most known galaxies belong to this class. However, so far not much is known about the physical structure and nature of these objects.
Aims: Our aim is to analyse the Lyα emission in a sample of high-redshift UV-continuum select…
Fine-Scale Structures of the Evershed Effect Observed by the Solar Optical Telescope aboard Hinode
Shimojo, Masumi; Tsuneta, Saku; Shimizu, Toshifumi +10 more
The small-scale structure of the Evershed effect is being studied using data obtained by the Spectropolarimeter and the Broadband Filter Imager of the Solar Optical Telescope aboard Hinode. We find that the Evershed flow starts at the leading edge of inwardly migrating bright penumbral grains, and turns to nearly a horizontal flow preferentially i…
IGR J16194-2810: a new symbiotic X-ray binary
Masetti, N.; Charles, P. A.; Bird, A. J. +7 more
We here report on the multiwavelength study which led us to the identification of X-ray source IGR J16194-2810 as a new Symbiotic X-ray Binary (SyXB), that is, a rare type of Low Mass X-ray Binary (LMXB) composed of a M-type giant and a compact object. Using the accurate X-ray position allowed by Swift/XRT data, we pinpointed the optical counterpa…
On the Progenitors of Two Type II-P Supernovae in the Virgo Cluster
Van Dyk, Schuyler D.; Filippenko, Alexei V.; Foley, Ryan J. +3 more
Direct identification of the progenitors of supernovae (SNe) is rare because of the required spatial resolution and depth of the archival data prior to the SN explosions. Here we report on the identification of the progenitors of two nearby SNe in the Virgo Cluster: SN 2006my in NGC 4651 and SN 2006ov in M61. We obtained high-quality ground-based …
Hubble Space Telescope Imaging of the Expanding Nebular Remnant of the 2006 Outburst of the Recurrent Nova RS Ophiuchi
Bond, Howard E.; Eyres, S. P. S.; Evans, A. +5 more
We report Hubble Space Telescope imaging obtained 155 days after the 2006 outburst of RS Ophiuchi. We detect extended emission in both [O III] λ5007 and [Ne V] λ3426 lines. In both lines, the remnant has a double ring structure. The east-west orientation and total extent of these structures (580+/-50 AU at d=1.6 kpc) is consistent with that expect…
Elemental abundances of Galactic bulge planetary nebulae from optical recombination lines
Wang, W.; Liu, X. -W.
Deep long-slit optical spectrophotometric observations are presented for 25 Galactic bulge planetary nebulae (GBPNe) and six Galactic disc planetary nebulae (GDPNe). The spectra, combined with archival ultraviolet (UV) spectra obtained with the International Ultraviolet Explorer and infrared spectra obtained with the Infrared Space Observatory, ha…