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The He II Proximity Effect and The Lifetime of Quasars
Worseck, G.; Hennawi, J. F.; McQuinn, M. +1 more
The lifetime of quasars is fundamental for understanding the growth of supermassive black holes, and is an important ingredient in models of the reionization of the intergalactic medium (IGM). However, despite various attempts to determine quasar lifetimes, current estimates from a variety of methods are uncertain by orders of magnitude. This work…
Discovery of an Extremely Wide-angle Bipolar Outflow in AFGL 5142
Kim, Kee-Tae; Lee, Jeong-Eun; Li, Di +12 more
Most bipolar outflows are associated with individual young stellar objects and have small opening angles. Here we report the discovery of an extremely wide-angle (∼180°) bipolar outflow (“EWBO”) in a cluster forming region AFGL 5142 from low-velocity emission of the HCN (3-2) and HCO+ (3-2) lines. This bipolar outflow is along a north-w…
Study of Swift/Bat Selected Low-luminosity Active Galactic Nuclei Observed with Suzaku
Ueda, Yoshihiro; Kawamuro, Taiki; Terashima, Yuichi +2 more
We systematically analyze the broadband (0.5-200 keV) X-ray spectra of hard X-ray (>10 keV) selected local low-luminosity active galactic nuclei (LLAGNs) observed with Suzaku and Swift/BAT. The sample consists of 10 LLAGNs detected with Swift/BAT with intrinsic 14-195 keV luminosities smaller than 1042 erg s-1 available in…
Light-curve Analysis of Neon Novae
Kato, Mariko; Hachisu, Izumi
We analyzed light curves of five neon novae, QU Vul, V351 Pup, V382 Vel, V693 CrA, and V1974 Cyg, and determined their white dwarf (WD) masses and distance moduli on the basis of theoretical light curves composed of free-free and photospheric emission. For QU Vul, we obtained a distance of d ∼ 2.4 kpc, reddening of E(B - V) ∼ 0.55, and WD mass of …
The Magnetic Classification of Solar Active Regions 1992-2015
Jaeggli, S. A.; Norton, A. A.
The purpose of this Letter is to address a blindspot in our knowledge of solar active region (AR) statistics. To the best of our knowledge, there are no published results showing the variation of the Mount Wilson magnetic classifications as a function of solar cycle based on modern observations. We show statistics for all ARs reported in the daily…
Stellar Mass-Gas-phase Metallicity Relation at 0.5 ≤ z ≤ 0.7: A Power Law with Increasing Scatter toward the Low-mass Regime
Barro, Guillermo; Pérez-González, Pablo G.; Hathi, Nimish P. +21 more
We present the stellar mass ({M}*)-gas-phase metallicity relation (MZR) and its scatter at intermediate redshifts (0.5≤slant z≤slant 0.7) for 1381 field galaxies collected from deep spectroscopic surveys. The star formation rate (SFR) and color at a given {M}* of this magnitude-limited (R≲ 24 AB) sample are representative of …
Transition Region and Chromospheric Signatures of Impulsive Heating Events. I. Observations
Warren, Harry P.; Crump, Nicholas A.; Reep, Jeffrey W. +1 more
We exploit the high spatial resolution and high cadence of the Interface Region Imaging Spectrograph (IRIS) to investigate the response of the transition region and chromosphere to energy deposition during a small flare. Simultaneous observations from the Reuven Ramaty High Energy Solar Spectroscopic Imager provide constraints on the energetic ele…
The Total Solar Irradiance Climate Data Record
Dewitte, Steven; Nevens, Stijn
We present the composite measurements of total solar irradiance (TSI) as measured by an ensemble of space instruments. The measurements of the individual instruments are put on a common absolute scale, and their quality is assessed by intercomparison. The composite time series is the average of all available measurements. From 1984 April to the pr…
Physical Properties of Spectroscopically Confirmed Galaxies at z ≥ 6. III. Stellar Populations from SED Modeling with Secure Lyα Emission and Redshifts
Ouchi, Masami; Shimasaku, Kazuhiro; Fan, Xiaohui +9 more
We present a study of stellar populations in a sample of spectroscopically confirmed Lyman-break galaxies (LBGs) and Lyα emitters (LAEs) at 5.7< z< 7. These galaxies have deep images from Subaru, the Hubble Space Telescope, and Spitzer/IRAC. We focus on 27 galaxies with IRAC detections, and characterize their stellar populations based on the…
A Hubble Space Telescope Study of the Enigmatic Milky Way Halo Globular Cluster Crater*
Dolphin, Andrew E.; Sills, Alison; Belokurov, Vasily +6 more
We analyze the resolved stellar populations of the faint stellar system, Crater, based on deep optical imaging taken with the Advanced Camera for Surveys on the Hubble Space Telescope. Crater’s color-magnitude diagram (CMD) extends ∼4 mag below the oldest main-sequence (MS) turnoff. Structurally, we find that Crater has a half-light radius of ∼20 …