Search Publications
Keck/MOSFIRE Spectroscopy of z = 7-8 Galaxies: Lyα Emission from a Galaxy at z = 7.66
Finkelstein, Steven L.; Dickinson, Mark; Fontana, Adriano +3 more
We report the results from some of the deepest Keck/Multi-Object Spectrometer For Infra-Red Exploration data yet obtained for candidate z ≳ 7 galaxies. Our data show one significant line detection with 6.5σ significance in our combined 10 hr of integration which is independently detected on more than one night, thus ruling out the possibility that…
A Spectroscopic Study of Blue Supergiant Stars in the Sculptor Galaxy NGC 55: Chemical Evolution and Distance
Kudritzki, R. P.; Bresolin, F.; Przybilla, N. +5 more
Low-resolution (4.5-5 Å) spectra of 58 blue supergiant stars distributed over the disk of the Magellanic spiral galaxy NGC 55 in the Sculptor group are analyzed by means of non-LTE techniques to determine stellar temperatures, gravities, and metallicities (from iron peak and α-elements). A metallicity gradient of -0.22 ± 0.06 dex/R 25 i…
Three-dimensional Distribution of Ejecta in Supernova 1987A at 10,000 Days
Larsson, J.; Sollerman, J.; Lundqvist, P. +19 more
Due to its proximity, SN 1987A offers a unique opportunity to directly observe the geometry of a stellar explosion as it unfolds. Here we present spectral and imaging observations of SN 1987A obtained ∼10,000 days after the explosion with HST/STIS and VLT/SINFONI at optical and near-infrared wavelengths. These observations allow us to produce the …
Why is a Flare-rich Active Region CME-poor?
Wang, Yuming; Shen, Chenglong; Wang, Jingxiu +6 more
Solar active regions (ARs) are the major sources of two of the most violent solar eruptions, namely flares and coronal mass ejections (CMEs). The largest AR in the past 24 years, NOAA AR 12192, which crossed the visible disk from 2014 October 17 to 30, unusually produced more than one hundred flares, including 32 M-class and 6 X-class ones, but on…
The Relation between Galaxy Structure and Spectral Type: Implications for the Buildup of the Quiescent Galaxy Population at 0.5 < z < 2.0
van der Wel, Arjen; Kriek, Mariska; Whitaker, Katherine E. +1 more
We present the relation between galaxy structure and spectral type, using a K-selected galaxy sample at 0.5 < z < 2.0. Based on similarities between the UV-to-NIR spectral energy distributions (SEDs), we classify galaxies into 32 spectral types. The different types span a wide range in evolutionary phases, and thus—in combination with availa…
An ALMA Search for Substructure, Fragmentation, and Hidden Protostars in Starless Cores in Chamaeleon I
Bourke, Tyler L.; Di Francesco, James; Johnstone, Doug +11 more
We present an Atacama Large Millimeter/submillimeter Array (ALMA) 106 GHz (Band 3) continuum survey of the complete population of dense cores in the Chamaeleon I molecular cloud. We detect a total of 24 continuum sources in 19 different target fields. All previously known Class 0 and Class I protostars in Chamaeleon I are detected, whereas all of …
First Results from the Faint Infrared Grism Survey (FIGS): First Simultaneous Detection of Lyα Emission and Lyman Break from a Galaxy at z = 7.51
Cimatti, A.; Gardner, Jonathan P.; Finkelstein, S. L. +22 more
Galaxies at high redshifts are a valuable tool for studying cosmic dawn, therefore it is crucial to reliably identify these galaxies. Here, we present an unambiguous and first simultaneous detection of both the Lyα emission and the Lyman break from a z=7.512 +/- 0.004 galaxy, observed in the Faint Infrared Grism Survey (FIGS). These spectra, taken…
The Black Hole-Bulge Mass Relation in Megamaser Host Galaxies
Greene, Jenny E.; van de Ven, Glenn; Seth, Anil +4 more
We present Hubble Space Telescope (HST) images for nine megamaser disk galaxies with the primary goal of studying photometric BH-galaxy scaling relations. The megamaser disks provide the highest-precision extragalactic BH mass measurements, while our high-resolution HST imaging affords us the opportunity to decompose the complex nuclei of their la…
HST Emission Line Galaxies at z ~ 2: Comparing Physical Properties of Lyman Alpha and Optical Emission Line Selected Galaxies
Finkelstein, Steven L.; Trump, Jonathan R.; Schneider, Donald P. +14 more
We compare the physical and morphological properties of z ∼ 2 Lyα emitting galaxies (LAEs) identified in the HETDEX Pilot Survey and narrow band studies with those of z ∼ 2 optical emission line selected galaxies (oELGs) identified via HST WFC3 infrared grism spectroscopy. Both sets of galaxies extend over the same range in stellar mass (7.5\lt {l…
Parallax of Galactic Cepheids from Spatially Scanning the Wide Field Camera 3 on the Hubble Space Telescope: The Case of SS Canis Majoris
Casertano, Stefano; Anderson, Jay; Filippenko, Alexei V. +10 more
We present a high-precision measurement of the parallax for the 12-day Cepheid SS Canis Majoris, obtained via spatial scanning with the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST). Spatial scanning enables astrometric measurements with a precision of 20-40 µas, an order of magnitude better than pointed observations. SS CMa…