Search Publications
Identification of a Wide, Low-Mass Multiple System Containing the Brown Dwarf 2MASS J0850359+105716
Burgasser, Adam J.; Faherty, Jacqueline K.; Bochanski, John J. +3 more
We report our discovery of NLTT 20346 as an M5+M6 companion system to the tight binary (or triple) L dwarf 2MASS J0850359+105716. This nearby (~31 pc), widely separated (~7700 AU) quadruple system was identified through a cross-match of proper motion catalogs. Follow-up imaging and spectroscopy of NLTT 20346 revealed it to be a magnetically active…
Physical Structure of the Planetary Nebula NGC 3242 from the Hot Bubble to the Nebular Envelope
Guerrero, Martín A.; Chu, You-Hua; Gruendl, Robert A. +1 more
One key feature of the interacting stellar winds model of the formation of planetary nebulae (PNe) is the presence of shock-heated stellar wind confined in the central cavities of PNe. This so-called hot bubble should be detectable in X-rays. Here we present XMM-Newton observations of NGC 3242, a multiple-shell PN whose shell morphology is consist…
A Kinematic and Photometric Study of the Galactic Young Star Cluster NGC 7380
Chen, W. P.; Chen, Li; Sharma, Saurabh +6 more
We present proper motions, radial velocities, and a photometric study of the Galactic open cluster NGC 7380, which is associated with prominent emission nebulosity and dark molecular clouds. On the basis of the sample of highly probable member stars, the star cluster is found to be at a distance of 2.6 ± 0.4 kpc, has an age of around 4 Myr, and a …
Star Formation Properties in Barred Galaxies (SFB). I. Ultraviolet to Infrared Imaging and Spectroscopic Studies of NGC 7479
Wu, Hong; Cao, Chen; Meng, Xian-Min +1 more
Large-scale bars and minor mergers are important drivers for the secular evolution of galaxies. Based on ground-based optical images and spectra as well as ultraviolet data from the Galaxy Evolution Explorer and infrared data from the Spitzer Space Telescope, we present a multi-wavelength study of star formation properties in the barred galaxy NGC…
No Confirmed New Isolated Neutron Stars in the SDSS Data Release 4
Anderson, Scott F.; Haberl, Frank; Rosenfield, Philip +6 more
We report on follow-up observations of candidate X-ray-bright, radio-quiet isolated neutron stars (INSs) identified from correlations of the ROSAT All-Sky Survey (RASS) and the Sloan Digital Sky Survey (SDSS) Data Release 4 in Agüeros et al. We obtained Chandra X-ray Observatory exposures for 13 candidates in order to pinpoint the source of X-ray …
Close to the Dredge: Precise X-Ray C and N Abundances in λ Andromeda and Its Precocious Red Giant Branch Mixing Problem
Ness, J. -U.; Drake, Jeremy J.; Eldridge, John J. +2 more
Chandra LETG+HRC-S and XMM-Newton RGS spectra of H-like C and N lines formed in the corona of the primary star of the RS CVn-type binary λ And, a mildly metal-poor G8 III-IV first ascent giant that completed dredge-up ~50 Myr ago, have been used to make a precise measurement of its surface C/N ratio. We obtain the formal result [C/N] = 0.03 ± 0.07…
Multi-wavelength Observations of a Sample of Intermediate-luminosity Radio-loud Active Galaxies
Eracleous, Michael; Lewis, Karen T.; Sambruna, Rita M. +3 more
We present the results from exploratory (12-23 ks) XMM-Newton observations of six optically selected, radio-loud active galactic nuclei (AGNs), together with new radio data and a reanalysis of their archival SDSS spectra. The sources were selected in an effort to expand the current sample of radio-loud AGNs suitable for detailed X-ray spectroscopy…