Search Publications

Time-dependent Ionization in a Steady Flow in an MHD Model of the Solar Corona and Wind
DOI: 10.3847/1538-4357/aa93f3 Bibcode: 2017ApJ...850...26S

Reeves, Katharine K.; Raymond, John C.; Linker, Jon A. +3 more

Time-dependent ionization is important for diagnostics of coronal streamers and pseudostreamers. We describe time-dependent ionization calculations for a three-dimensional magnetohydrodynamic (MHD) model of the solar corona and inner heliosphere. We analyze how non-equilibrium ionization (NEI) influences emission from a pseudostreamer during the W…

2017 The Astrophysical Journal
SOHO 13
Size Dependence of Dust Distribution around the Earth Orbit
DOI: 10.3847/1538-3881/aa5ff3 Bibcode: 2017AJ....153..232U

Kaneda, Hidehiro; Ishihara, Daisuke; Kondo, Toru +3 more

In the solar system, interplanetary dust particles (IDPs) originating mainly from asteroid collisions and cometary activities drift to Earth orbit due to Poynting-Robertson drag. We analyzed the thermal emission from IDPs that was observed by the first Japanese infrared astronomical satellite, AKARI. The observed surface brightness in the trailing…

2017 The Astronomical Journal
AKARI 13
Comparing Coronal and Heliospheric Magnetic Fields over Several Solar Cycles
DOI: 10.3847/1538-4357/835/1/63 Bibcode: 2017ApJ...835...63K

Mursula, K.; Koskela, J. S.; Virtanen, I. I.

Here we use the PFSS model and photospheric data from Wilcox Solar Observatory, SOHO/MDI, SDO/HMI, and SOLIS to compare the coronal field with heliospheric magnetic field measured at 1 au, compiled in the NASA/NSSDC OMNI 2 data set. We calculate their mutual polarity match and the power of the radial decay, p, of the radial field using different s…

2017 The Astrophysical Journal
SOHO 13
Rotationally modulated variability and pulsations of the He-rich star CPD -62°2124 with an extraordinarily strong magnetic field
DOI: 10.1093/mnras/stx1994 Bibcode: 2017MNRAS.472..400H

Ilyin, I.; Hubrig, S.; Zejda, M. +5 more

A longitudinal magnetic field with a strength of 5.2 kG was recently detected in CPD -62°2124, which has a fractional main-sequence lifetime of about 60 per cent. Strongly magnetic early-B type chemically peculiar stars in an advanced evolutionary state are of special interest to understand the evolution of the angular momentum and spin-down time-…

2017 Monthly Notices of the Royal Astronomical Society
Gaia 13
Radar sounder evidence of thick, porous sediments in Meridiani Planum and implications for ice-filled deposits on Mars
DOI: 10.1002/2017GL074431 Bibcode: 2017GeoRL..44.9208W

Grant, John A.; Plaut, Jeffrey J.; Phillips, Roger J. +5 more

Meridiani Planum is one of the most intensely studied regions on Mars, yet little is known about the physical properties of the deposits below those examined by the Opportunity rover. We report the detection of subsurface echoes within the Meridiani Planum deposits from data obtained by the Mars Advanced Radar for Subsurface and Ionospheric Soundi…

2017 Geophysical Research Letters
MEx 13
The growth of typical star-forming galaxies and their supermassive black holes across cosmic time since z ∼ 2
DOI: 10.1093/mnras/stw2295 Bibcode: 2017MNRAS.464..303C

Smail, Ian; Sobral, David; Harrison, Chris +5 more

Understanding galaxy formation and evolution requires studying the interplay between the growth of galaxies and the growth of their black holes across cosmic time. Here, we explore a sample of Hα-selected star-forming galaxies from the High Redshift Emission Line Survey and use the wealth of multiwavelength data in the Cosmic Evolution Survey fiel…

2017 Monthly Notices of the Royal Astronomical Society
Herschel 13
Search for very high-energy gamma-ray emission from the microquasar Cygnus X-1 with the MAGIC telescopes
DOI: 10.1093/mnras/stx2087 Bibcode: 2017MNRAS.472.3474A

Maraschi, L.; Covino, S.; Antonelli, L. A. +144 more

The microquasar Cygnus X-1 displays the two typical soft and hard X-ray states of a black hole transient. During the latter, Cygnus X-1 shows a one-sided relativistic radio-jet. Recent detection of the system in the high energy (HE; E ≳ 60 MeV) gamma-ray range with Fermi-LAT associates this emission with the outflow. Former MAGIC observations reve…

2017 Monthly Notices of the Royal Astronomical Society
INTEGRAL 13
Thermophysical characteristics of the large main-belt asteroid (349) Dembowska
DOI: 10.1093/mnras/stx2089 Bibcode: 2017MNRAS.472.2388Y

Ip, Wing-Huen; Yu, Liang Liang; Ji, Jianghui +1 more

(349) Dembowska is a large, bright main-belt asteroid that has a fast rotation and an oblique spin axis. It might have experienced partial melting and differentiation. We constrain Dembowska's thermophysical properties, such as thermal inertia, roughness fraction, geometric albedo and effective diameter within 3σ uncertainty of Γ =20^{+12}_{-7} Jm…

2017 Monthly Notices of the Royal Astronomical Society
AKARI 13
Spatially Resolved Patchy Lyα Emission within the Central Kiloparsec of a Strongly Lensed Quasar Host Galaxy at z = 2.8
DOI: 10.3847/2041-8213/aa831a Bibcode: 2017ApJ...845L..14B

Acharyya, Ayan; Rigby, Jane R.; Bian, Fuyan +10 more

We report the detection of extended Lyα emission from the host galaxy of SDSS J2222+2745, a strongly lensed quasar at z = 2.8. Spectroscopic follow-up clearly reveals extended Lyα in emission between two images of the central active galactic nucleus (AGN). We reconstruct the lensed quasar host galaxy in the source plane by applying a strong lens m…

2017 The Astrophysical Journal
eHST 13
Characterizing the Stellar Population of NGC 1980
DOI: 10.3847/1538-3881/aa74df Bibcode: 2017AJ....154...29K

Kounkel, Marina; Hartmann, Lee; Calvet, Nuria +1 more

NGC 1980 is a young cluster that is located about 0.°5 south of the Orion Nebula Cluster (ONC). Recent studies by Bouy et al. and Pillitteri et al. have suggested that NGC 1980 contains an older population of stars compared to a much younger ONC, and that it belongs to a foreground population that may be located in front of the Orion A molecular g…

2017 The Astronomical Journal
Gaia 13