Science Archives Publication System

The 2014 X-Ray Minimum of η Carinae as Seen by Swift

DOI: 10.3847/1538-4357/aa6347 Bibcode: 2017ApJ...838...45C

Gull, T. R.; Corcoran, M. F.; Madura, T. I. +10 more

We report on Swift X-ray Telescope observations of Eta Carinae (η Car), an extremely massive, long-period, highly eccentric binary obtained during the 2014.6 X-ray minimum/periastron passage. These observations show that η Car may have been particularly bright in X-rays going into the X-ray minimum state, while the duration of the 2014 X-ray minim…

2017 • The Astrophysical Journal

XMM-Newton 33

Observations of Ellerman bomb emission features in He I D₃ and He I 10 830 Å

DOI: 10.1051/0004-6361/201629266 Bibcode: 2017A&A...598A..33L

Joshi, Jayant; Leenaarts, Jorrit; Libbrecht, Tine +2 more

Context. Ellerman bombs (EBs) are short-lived emission features, characterised by extended wing emission in hydrogen Balmer lines. Until now, no distinct signature of EBs has been found in the He I 10 830 Å line, and conclusive observations of EBs in He I D₃ have never been reported.
Aims: We aim to study the signature of EBs in ne…

2017 • Astronomy and Astrophysics

IRIS 33

Star formation towards the Galactic H II region RCW 120. Herschel observations of compact sources

DOI: 10.1051/0004-6361/201629379 Bibcode: 2017A&A...600A..93F

Abergel, A.; Bernard, J. -P.; Hill, T. +16 more

Context. The expansion of H II regions can trigger the formation of stars. An overdensity of young stellar objects is observed at the edges of H II regions but the mechanisms that give rise to this phenomenon are not clearly identified. Moreover, it is difficult to establish a causal link between H II -region expansion and the star formation obser…

2017 • Astronomy and Astrophysics

Herschel Planck 33

Stationary waves and slowly moving features in the night upper clouds of Venus

DOI: 10.1038/s41550-017-0187 Bibcode: 2017NatAs...1E.187P

Hueso, R.; Sánchez-Lavega, A.; Kouyama, T. +9 more

At the cloud top level of Venus (65-70 km altitude) the atmosphere rotates 60 times faster than the underlying surface—a phenomenon known as superrotation^1,2. Whereas on Venus's dayside the cloud top motions are well determined^3,4,5,6 and Venus general circulation models predict the mean zonal flow at the upper clouds to be s…

2017 • Nature Astronomy

VenusExpress 33

High-resolution Spectroscopy of Extremely Metal-poor Stars from SDSS/SEGUE. III. Unevolved Stars with [Fe/H] ≲ -3.5

DOI: 10.3847/1538-3881/aa7a08 Bibcode: 2017AJ....154...52M

Honda, Satoshi; Beers, Timothy C.; Lee, Young Sun +2 more

We present elemental abundances for eight unevolved extremely metal-poor (EMP) stars with {T}_{eff}> 5500 {{K}}, among which seven have [{Fe}/{{H}}]< -3.5. The sample is selected from the Sloan Digital Sky Survey/Sloan Extension for Galactic Understanding and Exploration (SDSS/SEGUE) and our previous high-resolution spectroscopic f…

2017 • The Astronomical Journal

Gaia 33

Strong H I Lyman-α variations from an 11 Gyr-old host star: a planetary origin?

DOI: 10.1051/0004-6361/201730542 Bibcode: 2017A&A...602A.106B

Thomas, N.; Ehrenreich, D.; Lovis, C. +8 more

Kepler-444 provides a unique opportunity to probe the atmospheric composition and evolution of a compact system of exoplanets smaller than the Earth. Five planets transit this bright K star at close orbital distances, but they are too small for their putative lower atmosphere to be probed at optical/infrared wavelengths. We used the Space Telescop…

2017 • Astronomy and Astrophysics

eHST 33

The Origin of the Iron-rich Knot in Tycho’s Supernova Remnant

DOI: 10.3847/1538-4357/834/2/124 Bibcode: 2017ApJ...834..124Y

Petre, Robert; Yamaguchi, Hiroya; Hughes, John P. +5 more

X-ray observations of supernova remnants (SNRs) allow us to investigate the chemical inhomogeneity of ejecta, offering unique insight into the nucleosynthesis in supernova explosions. Here we present detailed imaging and spectroscopic studies of the “Fe knot” located along the eastern rim of the Type Ia SNR Tycho (SN 1572) using Suzaku and Chandra…

2017 • The Astrophysical Journal

Suzaku 33

The Impact of the Group Environment on the O VI Circumgalactic Medium

DOI: 10.3847/1538-4357/aa7743 Bibcode: 2017ApJ...844...23P

Charlton, Jane C.; Kacprzak, Glenn G.; Churchill, Christopher W. +3 more

We present a study comparing O VI λλ1031, 1037 doublet absorption found toward group galaxy environments to that of isolated galaxies. The O VI absorption in the circumgalactic medium (CGM) of isolated galaxies has been studied previously by the “Multiphase Galaxy Halos” survey, where the kinematics and absorption properties of the CGM have been i…

2017 • The Astrophysical Journal

eHST 33

Doppler Shift Oscillations from a Hot Line Observed by IRIS

DOI: 10.3847/1538-4357/aa9073 Bibcode: 2017ApJ...849..113L

Huang, Y.; Li, D.; Zhang, Q. M. +4 more

We present a detailed investigation of the Doppler shift oscillations in a hot loop during an M7.1 flare on 2014 October 27 observed by the Interface Region Imaging Spectrograph. The periodic oscillations are observed in the Doppler shift of Fe xxi 1354.09 Å (log T∼ 7.05), and the dominant period is about 3.1 minutes. However, such 3.1 minute osci…

2017 • The Astrophysical Journal

Hinode IRIS 33

Strongly Misaligned Triple System in SR 24 Revealed by ALMA

DOI: 10.3847/1538-4357/aa7d51 Bibcode: 2017ApJ...845...10F

Fernández-López, M.; Zapata, L. A.; Gabbasov, R.

We report the detection of the 1.3 mm continuum and the molecular emission of the disks of the young triple system SR24 by analyzing ALMA (The Atacama Large Millimeter/Submillimter Array) subarcsecond archival observations. We estimate the mass of the disks (0.025 M _⊙ and 4 × 10^-5 M _⊕ for SR24S and SR24N, respectiv…

2017 • The Astrophysical Journal

eHST 33