Search Publications
The Collapse of the Wien Tail in the Coldest Brown Dwarf? Hubble Space Telescope Near-infrared Photometry of WISE J085510.83-071442.5
Cushing, Michael C.; Kirkpatrick, J. Davy; Gelino, Christopher R. +1 more
We present Hubble Space Telescope (HST) near-infrared photometry of the coldest known brown dwarf, WISE J085510.83-071442.5 (WISE 0855-0714). WISE 0855-0714 was observed with the Wide Field Camera 3 (WFC3) on board HST using the F105W, F125W, and F160W filters, which approximate the Y, J, and H near-infrared bands. WISE 0855-0714 is undetected at …
X-Ray Spectra of the High-mass X-Ray Binary 4U 1700-37 Using BeppoSAX, Suzaku, and RXTE Observations
Titarchuk, Lev; Seifina, Elena; Shaposhnikov, Nikolai
We present an X-ray spectral analysis of the high-mass binary 4U 1700-37 during its hard-soft state evolution. We use BeppoSAX, Suzaku, and Rossi X-ray Timing Explorer observations for this investigation. We argue that the X-ray broadband spectra during all of the spectral states can be adequately reproduced by a model consisting of a low-temperat…
Spatially Resolved Spectroscopy of Submillimeter Galaxies at z ≃ 2
Casey, Caitlin M.; Treister, E.; Bauer, F. E. +9 more
We present near-infrared integral-field spectroscopic observations targeting Hα in eight submillimeter galaxies (SMGs) at z = 1.3-2.5 using the Very Large Telescope/Spectrograph for Integral Field Observations in the Near Infrared, obtaining significant detections for six of them. The star formation rates derived from the Hα emission are ∼100 M
Multi-wavelength Study of Transition Region Penumbral Subarcsecond Bright Dots Using IRIS and NST
Xu, Yan; Liu, Chang; Wang, Haimin +4 more
Using high-resolution transition region (TR) observations taken by the Interface Region Imaging Spectrograph (IRIS) mission, Tian et al. revealed numerous short-lived subarcsecond bright dots (BDs) above sunspots (mostly located in the penumbrae), which indicate yet unexplained small-scale energy releases. Moreover, whether or not these subarcseco…
Narrow-line-width UV Bursts in the Transition Region above Sunspots Observed by IRIS
Fu, Hui; Madjarska, Maria S.; Li, Bo +5 more
Various small-scale structures abound in the solar atmosphere above active regions, playing an important role in the dynamics and evolution therein. We report on a new class of small-scale transition region structures in active regions, characterized by strong emissions but extremely narrow Si IV line profiles as found in observations taken with t…
The Overlooked Role of Stellar Variability in the Extended Main Sequence of LMC Intermediate-age Clusters
Contreras Ramos, R.; Vivas, A. K.; Strader, J. +2 more
Intermediate-age star clusters in the Large Magellanic Cloud show extended main sequence turnoffs (MSTOs) that are not consistent with a canonical single stellar population. These broad turnoffs have been interpreted as evidence for extended star formation and/or stellar rotation. Since most of these studies use single frames per filter to do the …
A Comprehensive Archival Chandra Search for X-Ray Emission from Ultracompact Dwarf Galaxies
Greene, Jenny E.; Mulchaey, John; Pandya, Viraj
We present the first comprehensive archival study of the X-ray properties of ultracompact dwarf (UCD) galaxies, with the goal of identifying weakly accreting central black holes in UCDs. Our study spans 578 UCDs distributed across 13 different host systems, including clusters, groups, fossil groups, and isolated galaxies. Of the 336 spectroscopica…
Hubble Space Telescope Constraints on the Winds and Astrospheres of Red Giant Stars
Harper, Graham M.; Wood, Brian E.; Müller, Hans-Reinhard
We report on an ultraviolet spectroscopic survey of red giants observed by the Hubble Space Telescope, focusing on spectra of the Mg II h and k lines near 2800 Å in order to study stellar chromospheric emission, winds, and astrospheric absorption. We focus on spectral types between K2 III and M5 III, a spectral type range with stars that are nonco…
A Candidate Planetary-mass Object with a Photoevaporating Disk in Orion
Fang, Min; Pascucci, Ilaria; Apai, Dániel +2 more
In this work, we report the discovery of a candidate planetary-mass object with a photoevaporating protoplanetary disk, Proplyd 133-353, which is near the massive star θ 1 Ori C at the center of the Orion Nebula Cluster (ONC). The object was known to have extended emission pointing away from θ 1 Ori C, indicating ongoing exte…
Evidence from SOFIA Imaging of Polycyclic Aromatic Hydrocarbon Formation along a Recent Outflow in NGC 7027
Sahai, R.; Ressler, M. E.; Lau, R. M. +1 more
We report spatially resolved (FWHM ∼ 3.″8-4.″6) mid-IR imaging observations of the planetary nebula (PN) NGC 7027 taken with the 2.5 m telescope on board the Stratospheric Observatory for Infrared Astronomy (SOFIA). Images of NGC 7027 were acquired at 6.3, 6.6, 11.1, 19.7, 24.2, 33.6, and 37.1 µ {{m}} using the Faint Object Infrared Camera f…