Search Publications
The Globular Cluster Luminosity Function and Specific Frequency in Dwarf Elliptical Galaxies
Miller, Bryan W.; Lotz, Jennifer M.
The globular cluster luminosity function, specific globular cluster frequency, SN, specific globular cluster mass, TMP, and globular cluster mass fraction in dwarf elliptical galaxies are explored using the full 69 galaxy sample of the HST WFPC2 Dwarf Elliptical Galaxy Snapshot Survey. The GCLFs of the dEs are well represente…
Star Formation via the Little Guy: A Bayesian Study of Ultracool Dwarf Imaging Surveys for Companions
Allen, Peter R.
I have undertaken a comprehensive statistical investigation of the ultracool dwarf companion distribution (spectral type M6 and later). Utilizing a Bayesian algorithm, I tested models of the companion distribution against data from an extensive set of space and ground-based imaging observations of nearby ultracool dwarfs. My main conclusions are f…
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 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…
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…
Direct Observation of High-Speed Plasma Outflows Produced by Magnetic Reconnection in Solar Impulsive Events
Qiu, Jiong; Wang, Tongjiang; Sui, Linhui
Spectroscopic observations of a solar limb flare recorded by SUMER on SOHO reveal for the first time hot, fast magnetic reconnection outflows in the corona. As the reconnection site rises across the SUMER spectrometer slit, significant blue- and redshift signatures are observed in sequence in the Fe XIX line, reflecting upflows and downflows of ho…
MAGIC Upper Limits on the Very High Energy Emission from Gamma-Ray Bursts
Bastieri, D.; Ciprini, S.; Longo, F. +141 more
During its first data cycle, between 2005 and the beginning of 2006, the fast repositioning system of the MAGIC telescope allowed the observation of nine different gamma-ray bursts as possible sources of very high energy γ-rays. These observations were triggered by alerts from Swift, HETE-2, and INTEGRAL; they started as quickly as possible after …
An Increase in the Faint Red Galaxy Population in Massive Clusters since z ~ 0.5
Kneib, J. -P.; Smith, G. P.; Smail, Ian +4 more
We compare the luminosity functions for red galaxies lying on the rest-frame (U-V) color-magnitude sequence in a homogeneous sample of 10 X-ray-luminous clusters from the MACS survey at z~0.5 to a similarly selected X-ray cluster sample at z~0.1. We exploit deep Hubble Space Telescope ACS imaging in the F555W and F814W passbands of the central 1.2…