Search Publications
Detection of [Ne II] Emission from Young Circumstellar Disks
Pascucci, I.; Carpenter, J. M.; Meyer, M. R. +9 more
We report the detection of [Ne II] emission at 12.81 µm in four out of the six optically thick dust disks observed as part of the FEPS Spitzer Legacy program. In addition, we detect a H I (7-6) emission line at 12.37 µm from the source RX J1852.3-3700. Detections of [Ne II] lines are favored by low mid-infrared excess emission. Both st…
Are ``EIT Waves'' Fast-Mode MHD Waves?
DeForest, C. E.; Stenflo, J. O.; Wills-Davey, M. J.
We examine the nature of large-scale, coronal, propagating wave fronts (``EIT waves'') and find they are incongruous with solutions using fast-mode MHD plane-wave theory. Specifically, we consider the following properties: nondispersive single pulse manifestations, observed velocities below the local Alfvén speed, and different pulses which travel…
Deep FORS1 Observations of the Double Main Sequence of ω Centauri
Pancino, E.; Bellazzini, M.; Origlia, L. +3 more
We present the results of a deep photometric survey performed with the VLT FORS1 aimed at investigating the complex main-sequence structure of the stellar system ω Centauri. We confirm the presence of a double main sequence and identify its blue component (bMS) over a large field of view up to 26' from the cluster center. We found that bMS stars a…
The Compact X-Ray Source 1E 1547.0-5408 and the Radio Shell G327.24-0.13: A New Proposed Association between a Candidate Magnetar and a Candidate Supernova Remnant
Gelfand, Joseph D.; Gaensler, B. M.
We present new observations of the field centered on X-ray source 1E 1547.0-5408. Analysis of a new Chandra observation shows that it is unresolved at arcsecond resolution, and analysis of a new XMM-Newton observation shows that its X-ray spectrum is best described by an absorbed power-law and blackbody model. A comparison of the X-ray flux observ…
Galactic Bulges from Hubble Space Telescope NICMOS Observations: Central Galaxian Objects, and Nuclear Profile Slopes
Balcells, Marc; Graham, Alister W.; Peletier, Reynier F.
We have measured the central structural properties for a sample of S0-Sbc galaxies down to scales of ~10 pc using Hubble Space Telescope NICMOS images. Central star clusters are found in 58% of our sample. Their near-infrared luminosities scale with the host bulge luminosities, as reported in 2003 by Balcells and coworkers. In terms of photometric…
AEGIS: Host Galaxy Morphologies of X-Ray-selected and Infrared-selected Active Galactic Nuclei at 0.2 <= z < 1.2
Barmby, P.; Cooper, M. C.; Lin, L. +16 more
We visually and quantitatively determine the host galaxy morphologies of 94 intermediate-redshift (0.2<=z<1.2) active galactic nuclei (AGNs), selected using Chandra X-ray data and Spitzer mid-infrared data in the Extended Groth Strip. Using recently developed morphology measures, the second-order moment of the brightest 20% of a galaxy's flu…
Evidence for a Long-standing Top-heavy Initial Mass Function in the Central Parsec of the Galaxy
Genzel, R.; Martins, F.; Salaris, M. +10 more
We classify 329 late-type giants within 1 pc of Sgr A*, using the adaptive optics integral field spectrometer SINFONI on the VLT. These observations represent the deepest spectroscopic data set so far obtained for the Galactic center, reaching a 50% completeness threshold at the approximate magnitude of the helium-burning red clump (KS~…
The Role of Galaxy Interactions and Mergers in Star Formation at z<=1.3: Mid-Infrared Properties in the Spitzer First Look Survey
Helou, G.; Armus, L.; Appleton, P. N. +8 more
By combining the 0.12 deg2 F814W Hubble Space Telescope (HST) and Spitzer MIPS 24 µm imaging in the First Look Survey (FLS), we investigate the properties of interacting and merging mid-infrared bright and faint sources at 0.2<=z<=1.3. We find a marginally significant increase in the pair fraction for MIPS 24 µm detect…
The Low-Mass X-Ray Binary and Globular Cluster Connection in Virgo Cluster Early-Type Galaxies: Optical Properties
Sarazin, Craig L.; Jordán, Andrés; Côté, Patrick +6 more
LMXBs form efficiently in GCs. By combining Chandra and HST ACS observations of 11 massive early-type galaxies in the Virgo Cluster, we use the most accurate identification of LMXBs and GCs to date to explore the optical properties of 270 GCs with LMXBs and 6488 GCs without detectable X-ray emission. More massive, redder, and more compact GCs are …
The Optical Extragalactic Background Light: Revisions and Further Comments
Bernstein, Rebecca A.
We revise the measurements in our previous work of foreground zodiacal light (ZL) and diffuse Galactic light (DGL) that were used to measure the extragalactic background light (EBL). These changes result in a decrease of 8 and an increase of 0.3 in units of 10-9 ergs s-1 cm-2 sr-1 Å-1 (``cgs''…