Search Publications
Discovery of New Coronal Lines at 2.843 and 2.853 µm
DeLuca, Edward E.; Judge, Philip G.; Samra, Jenna E. +1 more
Two new emission features were observed during the 2017 August 21 total solar eclipse by a novel spectrometer, the Airborne Infrared Spectrometer (AIR-Spec), flown at 14.3 km altitude aboard the NCAR Gulfstream-V aircraft. We derive wavelengths in air of 2.8427 ± 0.00009 µm and 2.8529 ± 0.00008 µm. One of these lines belongs to the 3{{…
z ∼ 2.5-3 Ionizers in the GOODS-N Field
Barger, A. J.; Cowie, L. L.; Oesch, P. +4 more
We use deep F275W imaging from the Hubble Deep UV Legacy Survey (HDUV) and G280 grism spectroscopy from the Hubble Space Telescope/WFC3, along with new and archival optical spectra from Keck/DEIMOS, to search for candidate ionizing sources in the GOODS-N field at z ∼ 2.5-3. Spectroscopic identification of our UV-selected sources are 99% complete t…
Gradual Streamer Expansions and the Relationship between Blobs and Inflows
Hess, P.; Wang, Y. -M.
Coronal helmet streamers show a continual tendency to expand outward and pinch off, giving rise to flux ropes that are observed in white light as “blobs” propagating outward along the heliospheric current/plasma sheet. The blobs form within the r ∼ 2-6 R ⊙ heliocentric range of the Large Angle and Spectrometric Coronagraph (LASCO) C2 in…
Space-based Coronagraphic Imaging Polarimetry of the TW Hydrae Disk: Shedding New Light on Self-shadowing Effects
Debes, John H.; Schneider, Glenn; Chen, Christine H. +6 more
We present Hubble Space Telescope Near-Infrared Camera and Multi-Object Spectrometer coronagraphic imaging polarimetry of the TW Hydrae protoplanetary disk. These observations simultaneously measure the total and polarized intensity, allowing direct measurement of the polarization fraction across the disk. In accord with the self-shadowing hypothe…
Size Distributions of Solar Proton Events and Their Associated Soft X-Ray Flares: Application of the Maximum Likelihood Estimator
D'Huys, Elke; Cliver, Edward W.
We use the maximum likelihood estimator to determine the slope (α) of the power-law size distribution of the peak proton fluxes of a subsampled set of 106 ∼ 25 MeV solar energetic proton (SEP) events from 1997 to 2016 associated with western hemisphere soft X-ray (SXR) flares: α = 1.28 ± 0.03. For the peak SXR fluxes of a subsample of 110 SEP-asso…
A Multiline Study of a High-mass Young Stellar Object in the Small Magellanic Cloud with ALMA: The Detection of Methanol Gas at 0.2 Solar Metallicity
Onaka, Takashi; Aikawa, Yuri; Shimonishi, Takashi +5 more
We report the results of subparsec-scale submillimeter observations toward an embedded high-mass young stellar object in the Small Magellanic Cloud (SMC) with ALMA. Complementary infrared data obtained with the AKARI satellite and the Gemini South telescope are also presented. The target infrared point source is spatially resolved into two dense m…
The Evolution of Protoplanetary Disks: Probing the Inner Disk of Very Low Accretors
Reiter, Megan; Calvet, Nuria; Briceño, César +7 more
We report FUV, optical, and NIR observations of three T Tauri stars in the Orion OB1b subassociation with Hα equivalent widths consistent with low or absent accretion and various degrees of excess flux in the mid-infrared. We aim to search for evidence of gas in the inner disk in HST Advanced Camera for Surveys/Solar Blind Channel spectra, and to …
Herschel Observations of Protoplanetary Disks in Lynds 1641
Kim, Kyoung Hee; Fischer, William J.; Calvet, Nuria +7 more
We analyze Herschel Space Observatory observations of 104 young stellar objects with protoplanetary disks in the ∼1.5 Myr star-forming region Lynds 1641 (L1641) within the Orion A Molecular Cloud. We present spectral energy distributions from the optical to the far-infrared including new photometry from the Herschel Photodetector Array Camera and …
Red Supergiants in the JWST Era. I. Near-IR Photometric Diagnostics
Levesque, Emily M.
The Near Infrared Camera (NIRCam) on the James Webb Space Telescope (JWST) will be an incredibly powerful instrument for studying red supergiants (RSGs). The high luminosities and red peak wavelengths of these stars make them ideal targets for JWST/NIRCam. With effective photometric diagnostics in place, imaging RSG populations in multiple filters…
GalMod: A Galactic Synthesis Population Model
Grebel, Eva K.; Zeidler, Peter; Crnojević, Denija +7 more
We present a new Galaxy population synthesis Model, GalMod. GalMod is a star-count model featuring an asymmetric bar/bulge as well as spiral arms and related extinction. The model, initially introduced in Pasetto et al., has been here completed with a central bar, a new bulge description, new disk vertical profiles, and several new bolometric corr…