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HST Grism Confirmation of Two z ∼ 2 Structures from the Clusters around Radio-loud AGN (CARLA) Survey
Noirot, Gaël; Gonzalez, Anthony H.; Stern, Daniel +10 more
Using Hubble Space Telescope slitless grism data, we report the spectroscopic confirmation of two distant structures at z∼ 2 associated with powerful high-redshift radio-loud active galactic nuclei (AGNs). These rich structures, likely (forming) clusters, are among the most distant structures currently known, and were identified on the basis of Sp…
Submillimeter Polarization Spectrum in the Vela C Molecular Cloud
Ward-Thompson, Derek; Fissel, Laura M.; Nakamura, Fumitaka +27 more
Polarization maps of the Vela C molecular cloud were obtained at 250, 350, and 500 µm during the 2012 flight of the balloon-borne telescope BLASTPol. These measurements are used in conjunction with 850 µm data from Planck to study the submillimeter spectrum of the polarization fraction for this cloud. The spectrum is relatively flat an…
The Possible Detection of a Binary Companion to a Type Ibn Supernova Progenitor
Maund, J. R.; Mattila, S.; Pastorello, A. +2 more
We present late-time observations of the site of the Type Ibn supernova (SN) 2006jc, acquired with the Hubble Space Telescope Advanced Camera for Surveys. A faint blue source is recovered at the SN position, with brightness {m}F435W=26.76+/- 0.20, {m}F555W=26.60+/- 0.23 and {m}F625W=26.32+/- 0.19 mag, although ther…
The Nature and Frequency of the Gas Outbursts in Comet 67P/Churyumov-Gerasimenko Observed by the Alice Far-ultraviolet Spectrograph on Rosetta
Parker, Joel Wm.; Bertaux, Jean-Loup; Stern, S. Alan +7 more
Alice is a far-ultraviolet imaging spectrograph on board Rosetta that, among multiple objectives, is designed to observe emissions from various atomic and molecular species from within the coma of comet 67P/Churyumov-Gerasimenko. The initial observations, made following orbit insertion in 2014 August, showed emissions of atomic hydrogen and oxygen…
Discovery of Broad Soft X-ray Absorption Lines from the Quasar Wind in PDS 456
Behar, E.; Turner, T. J.; Tombesi, F. +5 more
High-resolution soft X-ray spectroscopy of the prototype accretion disk wind quasar, PDS 456, is presented. Here, the XMM-Newton reflection grating spectrometer spectra are analyzed from the large 2013-2014 XMM-Newton campaign, consisting of five observations of approximately 100 ks in length. During the last observation (OBS. E), the quasar is at…
Ultra-narrow Negative Flare Front Observed in Helium-10830 Å Using the 1.6 m New Solar Telescope
Xu, Yan; Cao, Wenda; Liu, Chang +10 more
Solar flares are sudden flashes of brightness on the Sun and are often associated with coronal mass ejections and solar energetic particles that have adverse effects on the near-Earth environment. By definition, flares are usually referred to as bright features resulting from excess emission. Using the newly commissioned 1.6 m New Solar Telescope …
Detection of Lyman-alpha Emission from a Triply Imaged z = 6.85 Galaxy behind MACS J2129.4-0741
Fontana, Adriano; Pentericci, Laura; Schmidt, Kasper B. +13 more
We report the detection of Lyα emission at ∼9538 Å in the Keck/DEIMOS and Hubble Space Telescope WFC3 G102 grism data from a triply imaged galaxy at z=6.846+/- 0.001 behind galaxy cluster MACS J2129.4-0741. Combining the emission line wavelength with broadband photometry, line ratio upper limits, and lens modeling, we rule out the scenario that th…
The Impact of Accurate Extinction Measurements for X-Ray Spectral Models
Smith, Randall K.; Valencic, Lynne A.; Corrales, Lia
Interstellar extinction includes both absorption and scattering of photons from interstellar gas and dust grains, and it has the effect of altering a source's spectrum and its total observed intensity. However, while multiple absorption models exist, there are no useful scattering models in standard X-ray spectrum fitting tools, such as XSPEC. Non…
Magnetically Dominated Parallel Interstellar Filaments in the Infrared Dark Cloud G14.225-0.506
Zhang, Qizhou; Girart, Josep Miquel; Busquet, Gemma +2 more
The infrared dark cloud G14.225-0.506 (IRDC G14.2) displays a remarkable complex of parallel dense molecular filaments projected on the plane of the sky. Previous studies of dust emission and molecular lines have speculated whether magnetic fields could have played an important role in the formation of such elongated structures, which are hosts to…
The Red Sequence at Birth in the Galaxy Cluster Cl J1449+0856 at z = 2
Finoguenov, A.; Cimatti, A.; Daddi, E. +10 more
We use Hubble Space Telescope/WFC3 imaging to study the red population in the IR-selected, X-ray detected, low-mass cluster Cl J1449+0856 at z = 2, one of the few bona fide established clusters discovered at this redshift, and likely a typical progenitor of an average massive cluster today. This study explores the presence and significance of an e…