Search Publications
Stellar and Gaseous Abundances in M82
Maiolino, R.; Ranalli, P.; Comastri, A. +1 more
The near-infrared (near-IR) absorption spectra of starburst galaxies show several atomic and molecular lines from red supergiants that can be used to infer reliable stellar abundances. The metals locked in stars give a picture of the galaxy metallicity prior to the last burst of star formation. The enrichment of the new generation of stars born in…
Deep Luminosity Functions of Old and Intermediate-Age Globular Clusters in NGC 1316: Evidence for Dynamical Evolution of Second-Generation Globular Clusters
Gilmore, Diane; Whitmore, Bradley C.; Schweizer, François +1 more
The Advanced Camera for Surveys on board the Hubble Space Telescope has been used to obtain deep high-resolution images of the giant early-type galaxy NGC 1316, an obvious merger remnant. These observations supersede previous shallower imagery that revealed the presence of a population of metal-rich globular clusters of intermediate age (~3 Gyr). …
The Kinematics of Morphologically Selected z~2 Galaxies in the GOODS-North Field
Pettini, Max; Erb, Dawn K.; Shapley, Alice E. +2 more
We present near-IR spectra of Hα emission from 13 galaxies at z~2 in the Great Observatories Origins Deep Survey-North (GOODS-N) field. The galaxies were selected primarily because they appear to have elongated morphologies, and slits were aligned with the major axes (as determined from the rest-frame UV emission) of 11 of the 13. If the galaxies …
Wavelet Phase Coherence Analysis: Application to a Quiet-Sun Magnetic Element
Judge, Philip G.; Lites, Bruce W.; Mathioudakis, Mihalis +3 more
A new application of wavelet analysis is presented that utilizes the inherent phase information residing within the complex Morlet transform. The technique is applied to a weak solar magnetic network region, and the temporal variation of phase difference between TRACE 1700 Å and SOHO/SUMER C II 1037 Å intensities is shown. We present, for the firs…
Kinematics and Ultraviolet to Infrared Morphology of the Inner Homunculus of η Carinae
Corcoran, Michael F.; Walborn, Nolan R.; Hamann, Fred +12 more
We present the first ultraviolet and optical images of η Car and its circumstellar Homunculus nebula, obtained with the Advanced Camera for Surveys/High Resolution Camera (ACS/HRC) on board the Hubble Space Telescope (HST). Compared to those at visual wavelengths, UV images reveal excess emission 0.1"-0.6" from the central source along the minor a…
A Resolved Debris Disk around the G2 V Star HD 107146
Ford, H. C.; Williams, J. P.; Illingworth, G. D. +6 more
We present resolved scattered-light images of the debris disk around HD 107146, a G2 star 28.5 pc from the Sun. This is the first debris disk to be resolved in scattered light around a solar-type star. We observed it with the Hubble Space Telescope/Advanced Camera for Surveys coronagraph, using a 1.8" occulting spot and the F606W (broad V) and F81…
The N Enrichment and Supernova Ejection of the Runaway Microquasar LS 5039
Kaper, L.; Gies, D. R.; Huang, W. +3 more
We present an investigation of new optical and ultraviolet spectra of the mass donor star in the massive X-ray binary LS 5039. The optical band spectral line strengths indicate that the atmosphere is N-rich and C-poor, and we classify the stellar spectrum as type ON6.5 V((f)). The N-strong and C-weak pattern is also found in the stellar wind P Cyg…
HETE Observations of the Gamma-Ray Burst GRB 030329: Evidence for an Underlying Soft X-Ray Component
Sakamoto, T.; Hurley, K.; Boer, M. +30 more
An exceptionally intense gamma-ray burst, GRB 030329, was detected and localized by the instruments on board the High Energy Transient Explorer satellite (HETE) at 11:37:14 UT on 2003 March 29. The burst consisted of two ~10 s pulses of roughly equal brightness and an X-ray tail lasting more than 100 s. The energy fluence in the 30-400 keV energy …
Thermal and Nonthermal X-Rays from the Large Magellanic Cloud Superbubble 30 Doradus C
Ueno, Masaru; Koyama, Katsuji; Nakajima, Hiroshi +1 more
We report on the discovery of thermal and nonthermal X-rays from the shells of the superbubble (SB) 30 Dor C in the LMC. The X-ray morphology is a nearly circular shell with a radius of ~40 pc, which is bright on the northern and western sides. The spectra of the shells differ from region to region. The southern shell shows clear emission lines an…
Hypernovae/Gamma-Ray Bursts in the Galactic Center as Possible Sources of Galactic Positrons
Schanne, S.; Cordier, B.; Paul, J. +1 more
The observation of a strong and extended positron-electron line annihilation emission in the central regions of the Galaxy by the SPectrometer on the International Gamma-Ray Astrophysical Laboratory (INTEGRAL/SPI), consistent with the Galactic bulge geometry and without any counterpart in the gamma-ray range, neither at high energy nor in the 1809…