Search Publications
Optical and UV Spectra of the Remnant of SN 1885 (S And) in M31
Fesen, Robert A.; Hamilton, Andrew J. S.; Weil, Kathryn E. +1 more
We present multi-slit, 1D and 2D optical and UV spectra of the remnant of supernova 1885 (SN 1885; S And) taken using the Hubble Space Telescope’s Imaging Spectrograph (HST/STIS). These spectra of this probable subluminous Type Ia remnant, seen in silhouette against the central bulge of the Andromeda galaxy (M31), show strong and broad absorptions…
Lessons Learned from the Three-view Determination of CME Mass
de Koning, Curt A.
With only single-viewpoint, total-brightness images, it is not possible to calculate the true mass of a coronal mass ejection (CME) because total-brightness images do not contain any depth information. If two viewpoints are available, it has been suggested that total-brightness images might be used to simultaneously derive the CME deprojected mass…
“Dandelion” Filament Eruption and Coronal Waves Associated with a Solar Flare on 2011 February 16
Shibata, Kazunari; Takasao, Shinsuke; Ishii, Takako T. +11 more
Coronal disturbances associated with solar flares, such as Hα Moreton waves, X-ray waves, and extreme ultraviolet (EUV) coronal waves, are discussed herein in relation to magnetohydrodynamic fast-mode waves or shocks in the corona. To understand the mechanism of coronal disturbances, full-disk solar observations with high spatial and temporal reso…
XMM-Newton X-Ray Observations of LkCa 15: A T Tauri Star with a Formative Planetary System
Skinner, Stephen L.; Güdel, Manuel
High-resolution ground-based images of the T Tauri star LkCa 15 have revealed multiple companions that are thought to comprise a formative planetary system. The candidate protoplanets orbit at distances of ∼15-20 au within the dust-depleted inner region of the circumstellar disk. Because of its young age (∼1-4 Myr), LkCa 15 provides a benchmark sy…
Simultaneous Constraints on the Mass and Radius of Aql X-1 from Quiescence and X-Ray Burst Observations
Chen, Li; Falanga, Maurizio; Li, Zhaosheng +2 more
The measurement of neutron star mass and radius is one of the most direct ways to distinguish between various dense matter equations of state. The mass and radius of accreting neutron stars hosted in low-mass X-ray binaries can be constrained by several methods, including photospheric radius expansion from type I X-ray bursts and from quiescent sp…
Signatures of Hot Molecular Hydrogen Absorption from Protoplanetary Disks. I. Non-thermal Populations
Loyd, R. O. Parke; Kruczek, Nicholas; France, Kevin +2 more
The environment around protoplanetary disks (PPDs) regulates processes that drive the chemical and structural evolution of circumstellar material. We perform a detailed empirical survey of warm molecular hydrogen (H2) absorption observed against H I-Lyα (Lyα: λ1215.67) emission profiles for 22 PPDs, using archival Hubble Space Telescope…
The Carnegie-Chicago Hubble Program: Discovery of the Most Distant Ultra-faint Dwarf Galaxy in the Local Universe
Lee, Myung Gyoon; Jang, In Sung; Seibert, Mark +3 more
Ultra-faint dwarf galaxies (UFDs) are the faintest known galaxies, and due to their incredibly low surface brightness, it is difficult to find them beyond the Local Group. We report a serendipitous discovery of a UFD, Fornax UFD1, in the outskirts of NGC 1316, a giant galaxy in the Fornax cluster. The new galaxy is located at a projected radius of…
HST Detection of Extended Neutral Hydrogen in a Massive Elliptical at z = 0.4
Zahedy, Fakhri S.; Chen, Hsiao-Wen; Rauch, Michael +1 more
We report the first detection of extended neutral hydrogen (H I) gas in the interstellar medium (ISM) of a massive elliptical galaxy beyond z∼ 0. The observations utilize the doubly lensed images of QSO HE 0047-1756 at {z}{QSO}=1.676 as absorption-line probes of the ISM in the massive ({M}{star}≈ {10}11 {M}⊙ <…
The Nuclear X-Ray Emission-line Structure in NGC 2992 Revealed by Chandra-HETGS
Nowak, M. A.; Marshall, H. L.; Murphy, K. D.
We present the narrow emission-line structure revealed by a 135 ks Chandra observation of Seyfert galaxy NGC 2992, using the High Energy Transmission Grating Spectrometer. The source was observed in an historically low-flux state. Using a Bayesian Block search technique, we detected neutral Si Kα and S Kα fluorescence and two additional lines that…
Herschel Extreme Lensing Line Observations: [CII] Variations in Galaxies at Redshifts z=1-3
Carilli, Chris; Papovich, Casey; Strauss, Michael A. +14 more
We observed the [C II] line in 15 lensed galaxies at redshifts 1 < z < 3 using HIFI on the Herschel Space Observatory and detected 14/15 galaxies at 3σ or better. High magnifications enable even modestly luminous galaxies to be detected in [C II] with Herschel. The [C II] luminosity in this sample ranges from 8 × 107 L⊙…