Search Publications
Discovery of a Planetary-mass Companion to a Brown Dwarf in Taurus
Luhman, K. L.; McLeod, K. K.; Todorov, K.
We have performed a survey for substellar companions to young brown dwarfs in the Taurus star-forming region using the Wide Field Planetary Camera 2 on board the Hubble Space Telescope. In these data, we have discovered a candidate companion at a projected separation of 0farcs105 from one of the brown dwarfs, corresponding to 15 AU at the distance…
Seismic and Dynamical Solar Models. I. The Impact of the Solar Rotation History on Neutrinos and Seismic Indicators
Turck-Chièze, S.; Marques, J. P.; Palacios, A. +1 more
Solar activity and helioseismology show the limitation of the standard solar model and call for the inclusion of dynamical processes in both convective and radiative zones. In this paper, we concentrate on the radiative zone. We first recall the sensitivity of boron neutrinos to the microscopic physics included in solar standard and seismic models…
Star Formation History and X-ray Binary Populations: The Case of the Small Magellanic Cloud
Hatzidimitriou, D.; Zezas, A.; Antoniou, V. +1 more
Using Chandra, XMM-Newton, and optical photometric catalogs we study the young X-ray binary (XRB) populations of the Small Magellanic Cloud. We find that the Be/X-ray binaries (Be-XRBs) are observed in regions with star formation rate bursts ~25-60 Myr ago. The similarity of this age with the age of maximum occurrence of the Be phenomenon (~40 Myr…
Confirmation of X-ray Absorption by Warm-Hot Intergalactic Medium in the Sculptor Wall
Maiolino, Roberto; Canizares, Claude R.; Humphrey, Philip J. +5 more
In a previous paper, we reported a 3σ detection of an absorption line from the warm-hot intergalactic medium (WHIM) using the Chandra and XMM X-ray grating spectra of the blazar H2356-309, the sight line of which intercepts the Sculptor Wall, a large-scale superstructure of galaxies at z ~ 0.03. To verify our initial detection, we obtained a deep …
The Advanced Camera for Surveys Nearby Galaxy Survey Treasury. V. Radial Star Formation History of NGC 300
de Jong, Roelof S.; Williams, Benjamin F.; Gilbert, Karoline M. +13 more
We present new Hubble Space Telescope (HST) observations of NGC 300 taken as part of the Advanced Camera for Surveys Nearby Galaxy Survey Treasury (ANGST). Individual stars are resolved in these images down to an absolute magnitude of M F814W = 1.0 (below the red clump). We determine the star formation history of the galaxy in six rad…
Physical Conditions in a Coronal Mass Ejection from Hinode, Stereo, and SOHO Observations
Raymond, J. C.; Landi, E.; Hara, H. +1 more
In the present work, we analyze multiwavelength observations from Hinode, Solar and Heliospheric Observatory (SOHO), and STEREO of the early phases of a coronal mass ejection (CME). We use Hinode/EIS and SOHO/UVCS high-resolution spectra to measure the physical properties of the CME ejecta as a function of time at 1.1 and 1.9 solar radii. Hinode/X…
The Supermassive Black Hole and Dark Matter Halo of NGC 4649 (M60)
Gebhardt, Karl; Shen, Juntai
We apply the axisymmetric orbit superposition modeling to estimate the mass of the supermassive black hole (BH) and dark matter (DM) halo profile of NGC 4649. We have included data sets from the Hubble Space Telescope (HST), stellar, and globular cluster (GC) observations. Our modeling gives M • = (4.5 ± 1.0) × 109 M sun…
Surface Brightness Fluctuations in the Hubble Space Telescope ACS/WFC F814W Bandpass and an Update on Galaxy Distances
Jordán, Andrés; Tonry, John L.; Côté, Patrick +7 more
We measure surface brightness fluctuation (SBF) magnitudes in the F814W filter and (g 475 - I 814) colors for nine bright early-type Fornax cluster galaxies imaged with the Hubble Space Telescope Advanced Camera for Surveys (ACS). The goal is to achieve the first systematic SBF calibration for the ACS/F814W bandpass. Because …
SN 2007od: A Type IIP Supernova with Circumstellar Interaction
Welch, D. L.; Gallagher, J. S.; Barlow, M. J. +9 more
SN 2007od exhibits characteristics that have rarely been seen in a Type IIP supernova (SN). Optical V-band photometry reveals a very steep brightness decline between the plateau and nebular phases of ~4.5 mag, likely due to SN 2007od containing a low mass of 56Ni. The optical spectra show an evolution from normal Type IIP with broad Hα …
A Multiwavelength Study of a Sample of 70 µm Selected Galaxies in the COSMOS Field. I. Spectral Energy Distributions and Luminosities
Aussel, H.; Le Floc'h, E.; Kartaltepe, Jeyhan S. +26 more
We present a large robust sample of 1503 reliable and unconfused 70 µm selected sources from the multiwavelength data set of the Cosmic Evolution Survey. Using the Spitzer IRAC and MIPS photometry, we estimate the total infrared (IR) luminosity, L IR (8-1000 µm), by finding the best-fit template from several different templa…