Search Publications
Hot Molecular Gas in the Circumnuclear Disk
Togi, Aditya; Mills, Elisabeth A. C.; Kaufman, Michael
We present an analysis of archival Infrared Space Observatory observations of H2 for three 14\prime\prime × 20\prime\prime pointings in the central 3 pc of the Galaxy: toward the southwest region and northeast region of the Galactic center circumnuclear disk (CND), and toward the supermassive black hole Sgr A*. We …
A Multiwavelength Study of Nearby Millisecond Pulsar PSR J1400-1431: Improved Astrometry and an Optical Detection of Its Cool White Dwarf Companion
Ray, P. S.; Kaplan, D. L.; Lorimer, D. R. +16 more
In 2012, five high-school students involved in the Pulsar Search Collaboratory discovered the millisecond pulsar (MSP) PSR J1400-1431, and initial timing parameters were published in Rosen et al. a year later. Since then, we have obtained a phase-connected timing solution spanning five years, resolving a significant position discrepancy and measur…
A Statistical Comparison between Photospheric Vector Magnetograms Obtained by SDO/HMI and Hinode/SP
Sainz Dalda, Alberto
Since 2010 May 1, we have been able to study (almost) continuously the vector magnetic field in the Sun, thanks to two space-based observatories: the Solar Dynamics Observatory (SDO) and Hinode. Both are equipped with instruments able to measure the Stokes parameters of Zeeman-induced polarization of photospheric line radiation. But the observatio…
Solar Flare Termination Shock and Synthetic Emission Line Profiles of the Fe xxi 1354.08 Å Line
Li, Gang; Raymond, John; Guo, Lijia +1 more
Solar flares are among the most energetic phenomena that occur in the solar system. In the standard solar flare model, a fast mode shock, often referred to as the flare termination shock (TS), can exist above the loop-top source of hard X-ray emissions. The existence of the TS has been recently related to spectral hardening of a flare’s hard X-ray…
Little Blue Dots in the Hubble Space Telescope Frontier Fields: Precursors to Globular Clusters?
Elmegreen, Bruce G.; Elmegreen, Debra Meloy
Galaxies with stellar masses < {10}7.4 {M}⊙ and specific star formation rates {sSFR}> {10}-7.4 yr-1 were examined on images of the Hubble Space Telescope Frontier Field Parallels for Abell 2744 and MACS J0416.1-02403. They appear as unresolved “Little Blue Dots” (LBDs). They are less massive and h…
NuSTAR and XMM-Newton Observations of the 2015 Outburst Decay of GX 339-4
Stiele, H.; Kong, A. K. H.
The extent of the accretion disk in the low/hard state of stellar mass black hole X-ray binaries remains an open question. There is some evidence suggesting that the inner accretion disk is truncated and replaced by a hot flow, while the detection of relativistic broadened iron emission lines seems to require an accretion disk extending fully to t…
The Abundance of C2H4 in the Circumstellar Envelope of IRC+10216
Hinkle, K. H.; Cernicharo, J.; Fonfría, J. P. +3 more
High spectral resolution mid-IR observations of ethylene ({{{C}}}2{{{H}}}4) toward the AGB star IRC+10216 were obtained using the Texas Echelon Cross Echelle Spectrograph (TEXES) at the NASA Infrared Telescope Facility (IRTF). 80 ro-vibrational lines from the 10.5 µm vibrational mode {ν }7 with J ≲ 30 were de…
Attenuation Modified by DIG and Dust as Seen in M31
Schinnerer, Eva; Blanc, Guillermo A.; Kreckel, Kathryn +5 more
The spatial distribution of dust in galaxies affects the global attenuation, and hence inferred properties, of galaxies. We trace the spatial distribution of dust in five approximately kiloparsec fields of M31 by comparing optical attenuation with the total dust mass distribution. We measure the attenuation from the Balmer decrement using Integral…
Comparing Submillimeter Polarized Emission with Near-infrared Polarization of Background Stars for the Vela C Molecular Cloud
Ward-Thompson, Derek; Fissel, Laura M.; Nakamura, Fumitaka +27 more
We present a large-scale combination of near-infrared (near-IR) interstellar polarization data from background starlight with polarized emission data at submillimeter wavelengths for the Vela C molecular cloud. The near-IR data consist of more than 6700 detections probing a range of visual extinctions between 2 and 20 {mag} in and around the cloud…
Nature of the Diffuse Source and Its Central Point-like Source in SNR 0509-67.5
Pan, Kuo-Chuan; Ricker, Paul M.; Weisz, Daniel R. +7 more
We examine a diffuse emission region near the center of SNR 0509-67.5 to determine its nature. Within this diffuse region we observe a point-like source that is bright in the near-IR, but is not visible in the B and V bands. We consider an emission line observed at 6766 Å and the possibilities that it is Lyα, Hα, and [O II] λ3727. We examine the s…