Search Publications
The Rest-frame Ultraviolet Structure of 0.5 < z < 1.5 Galaxies
Koekemoer, Anton M.; Ravindranath, Swara; Gardner, Jonathan P. +8 more
We present the rest-frame UV wavelength dependence of the Petrosian-like half-light radius (r 50), and the concentration parameter for a sample of 198 star-forming galaxies at 0.5 < z < 1.5. We find a ~5% decrease in r 50 from 1500 Å to 3000 Å, with half-light radii at 3000 Å ranging from 0.6 kpc to 6 kpc. We also find …
Panchromatic Hubble Andromeda Treasury. IX. A Photometric Survey of Planetary Nebulae in M31
Williams, Benjamin F.; Gordon, Karl D.; Caldwell, Nelson +8 more
We search the Hubble Space Telescope (HST) Advanced Camera for Surveys and Wide Field Camera 3 broadband imaging data from the Panchromatic Hubble Andromeda Treasury (PHAT) survey to identify detections of cataloged planetary nebulae (PNs). Of the 711 PNs currently in the literature within the PHAT footprint, we find 467 detected in the broadband.…
Spitzer IRS Observations of the XA Region in the Cygnus Loop Supernova Remnant
Blair, William P.; Raymond, John C.; Borkowski, Kazimierz J. +5 more
We report on spectra of two positions in the XA region of the Cygnus Loop supernova remnant obtained with the InfraRed Spectrograph on the Spitzer Space Telescope. The spectra span the 10-35 µm wavelength range, which contains a number of collisionally excited forbidden lines. These data are supplemented by optical spectra obtained at the Wh…
Improved Determination of the Atmospheric Parameters of the Pulsating sdB Star Feige 48
Latour, M.; Chayer, P.; Green, E. M. +2 more
As part of a multifaceted effort to better exploit the asteroseismological potential of the pulsating sdB star Feige 48, we present an improved spectroscopic analysis of that star based on new grids of NLTE, fully line-blanketed model atmospheres. To that end, we gathered four high signal-to-noise ratio time-averaged optical spectra of varying spe…
Nature versus Nurture: Luminous Blue Variable Nebulae in and near Massive Stellar Clusters at the Galactic Center
Morris, M. R.; Lau, R. M.; Herter, T. L. +1 more
Three luminous blue variables (LBVs) are located in and near the Quintuplet Cluster at the Galactic center: the Pistol Star, G0.120-0.048, and qF362. We present imaging at 19, 25, 31, and 37 µm of the region containing these three LBVs, obtained with SOFIA using FORCAST. We argue that Pistol and G0.120-0.048 are identical "twins" that exhibi…
An Optical-Near-IR Study of a Triplet of Super Star Clusters in the Starburst Core of M82
O'Connell, R. W.; Rosa González, D.; Bastian, N. +8 more
We present HST/STIS optical and Gemini/NIFS near-IR IFU spectroscopy and archival Hubble Space Telescope (HST) imaging of the triplet of super star clusters (A1, A2, and A3) in the core of the M82 starburst. Using model fits to the Space Telescope Imaging Spectrograph (STIS) spectra and the weakness of red supergiant CO absorption features (appear…
Properties of M31. IV. Candidate Luminous Blue Variables from PAndromeda
Price, P. A.; Bianchi, L.; Chambers, K. C. +16 more
We perform a study on the optical and infrared photometric properties of known luminous blue variables (LBVs) in M31 using a sample of LBV candidates from the Local Group Galaxy Survey by Masset et al. We find that M31 LBV candidates show photometric variability ranging from 0.375 to 1.576 mag in r P1 during a 3 yr time span observed by…
Spatiotemporal Organization of Energy Release Events in the Quiet Solar Corona
Davila, Joseph M.; Uritsky, Vadim M.
Using data from the STEREO and SOHO spacecraft, we show that temporal organization of energy release events in the quiet solar corona is close to random, in contrast to the clustered behavior of flaring times in solar active regions. The locations of the quiet-Sun events follow the meso- and supergranulation pattern of the underling photosphere. T…
Comparison of Prestellar Core Elongations and Large-scale Molecular Cloud Structures in the Lupus I Region
Ward-Thompson, Derek; Fissel, Laura M.; Savini, Giorgio +28 more
Turbulence and magnetic fields are expected to be important for regulating molecular cloud formation and evolution. However, their effects on sub-parsec to 100 parsec scales, leading to the formation of starless cores, are not well understood. We investigate the prestellar core structure morphologies obtained from analysis of the Herschel-SPIRE 35…
Are the Faint Structures Ahead of Solar Coronal Mass Ejections Real Signatures of Driven Shocks?
Moon, Y. -J.; Lee, Kyoung-Sun; Kim, Sujin +3 more
Recently, several studies have assumed that the faint structures ahead of coronal mass ejections (CMEs) are caused by CME-driven shocks. In this study, we have conducted a statistical investigation to determine whether or not the appearance of such faint structures depends on CME speeds. For this purpose, we use 127 Solar and Heliospheric Observat…