Search Publications
The Origin of [C II] 158 µm Emission toward the H II Region Complex S235
Schneider, N.; Tremblin, P.; Zavagno, A. +9 more
Although the {}2{{{P}}}3/2-{}2{{{P}}}1/2 transition of [C II] at λ ≃ 158 µ {{m}} is known to be an excellent tracer of active star formation, we still do not have a complete understanding of where within star formation regions the emission originates. Here, we use SOFIA upGREAT observations of [C I…
Coordinated UV and X-Ray Spectroscopic Observations of the O-type Giant ξ Per: The Connection between X-Rays and Large-scale Wind Structure
Ignace, Richard; Massa, Derck; Oskinova, Lida +1 more
We present new, contemporaneous Hubble Space Telescope STIS and XMM-Newton observations of the O7 III(n)((f)) star ξ Per. We supplement the new data with archival IUE spectra, to analyze the variability of the wind lines and X-ray flux of ξ Per. The variable wind of this star is known to have a 2.086-day periodicity. We use a simple, heuristic spo…
Spectral Magnetic Helicity of Solar Active Regions between 2006 and 2017
Gosain, Sanjay; Brandenburg, Axel
We compute magnetic helicity and energy spectra from about 2485 patches of about 100 Mm side length on the solar surface using data from Hinode during 2006-2017. An extensive database is assembled where we list the magnetic energy and helicity, large- and small-scale magnetic helicity, mean current helicity density, fractional magnetic helicity, a…
A Joint NICER and XMM-Newton View of the “Magnificent” Thermally Emitting X-Ray Isolated Neutron Star RX J1605.3+3249
Enoto, Teruaki; Bogdanov, Slavko; Ray, Paul S. +11 more
Thermally emitting X-ray isolated neutron stars (NSs) represent excellent targets for testing cooling surface emission and atmosphere models, which are used to infer the physical parameters of the NS. Among the seven known members of this class, RX J1605.3+3249 is the only one that still lacks confirmation of its spin period. Here we analyze NICER…
Solar Active Region Heating Diagnostics from High-temperature Emission Using the MaGIXS
Golub, Leon; Winebarger, Amy R.; Warren, Harry P. +7 more
The relative amount of high-temperature plasma has been found to be a useful diagnostic to determine the frequency of coronal heating on sub-resolution structures. When the loops are infrequently heated, a broad emission measure (EM) over a wider range of temperatures is expected. A narrower EM is expected for high-frequency heating where the loop…
Monitoring the Superorbital Period Variation and Spin Period Evolution of SMC X-1
Enoto, Teruaki; Ueda, Yoshihiro; Hu, Chin-Ping +2 more
The X-ray pulsar SMC X-1 shows a superorbital modulation with an unstable cycle length in the X-ray band. We present its timing behaviors, including the spin, orbital, and superorbital modulations, beyond the end of the Rossi X-ray Timing Explorer mission. The time-frequency maps derived by the wavelet Z-transform and the Hilbert-Huang transform s…
Hubble Space Telescope Spectroscopy of a Planetary Nebula in an M31 Open Cluster: Hot-bottom Burning at 3.4 M ⊙
Bond, Howard E.; Ciardullo, Robin; Jacoby, George H. +1 more
We use imaging and spectroscopy from the Hubble Space Telescope (HST) to examine the properties of a bright planetary nebula (PN) projected within M31's young open cluster B477-D075. We show that the probability of a chance superposition of the PN on the cluster is small, ≲2%. Moreover, the radial velocity of the PN is the same as that of the clus…
The Atacama Cosmology Telescope: CO(J = 3 - 2) Mapping and Lens Modeling of an ACT-selected Dusty Star-forming Galaxy
Gallardo, Patricio A.; Huffenberger, Kevin M.; Hughes, John P. +13 more
We report Northern Extended Millimeter Array CO(J = 3 - 2) observations of the dusty star-forming galaxy ACT-S J020941+001557 at z = 2.5528, which was detected as an unresolved source in the Atacama Cosmology Telescope (ACT) equatorial survey. Our spatially resolved spectral line data support the derivation of a gravitational lens model from 37 in…
Benchmarking Substellar Evolutionary Models Using New Age Estimates for HD 4747 B and HD 19467 B
Crepp, Justin R.; White, Timothy R.; Brewer, John M. +5 more
Constraining substellar evolutionary models (SSEMs) is particularly difficult due to a degeneracy between the mass, age, and luminosity of a brown dwarf. In cases where a brown dwarf is found as a directly imaged companion to a star, as in HD 4747 and HD 19467, the mass, age, and luminosity of the brown dwarf are determined independently, making t…
A Wide-field Photometric Survey of Globular Clusters in the Peculiar Early-type Galaxy M85
Park, Byeong-Gon; Hwang, Narae; Lee, Myung Gyoon +4 more
We survey globular clusters (GCs) in M85 using ugi-band images of a 1° × 1° field obtained with the MegaCam at the 3.6 m Canada-France-Hawaii Telescope. We identify 1318 GC candidates with 20.0 mag < g 0 < 23.5 mag in the entire survey region. Their radial number density profile is well fit by a Sérsic profile with n = {2.58}…