Search Publications
Predicting GAIA's Parallax Distance to the Cygnus OB2 Association with Eclipsing Binaries
Kobulnicky, Henry A.; Lundquist, Michael J.; Vargas Álvarez, Carlos A. +2 more
The Cygnus OB2 Association is one of the nearest and largest collections of massive stars in the Galaxy. Situated at the heart of the “Cygnus X” complex of star-forming regions and molecular clouds, its distance has proven elusive owing to the ambiguous nature of kinematic distances along this ℓ ≃ 80° sightline and the heavy, patchy extinction. In…
On the Electron-to-Neutral Number Density Ratio in the Coma of Comet 67P/Churyumov-Gerasimenko: Guiding Expression and Sources for Deviations
Edberg, N. J. T.; Vigren, E.; Galand, M. +3 more
We compute partial photoionization frequencies of H2O, CO2, and CO, the major molecules in the coma of comet 67P/Churyumov-Gerasimenko, the target comet of the ongoing ESA Rosetta mission. Values are computed from Thermosphere Ionosphere Mesosphere Energy and Dynamics/Solar EUV Experiment solar EUV spectra for 2014 August 1, …
Variations between Dust and Gas in the Diffuse Interstellar Medium
Heiles, Carl; Reach, William T.; Bernard, Jean-Philippe
Using the Planck far-infrared and Arecibo GALFA 21 cm line surveys, we identified a set of isolated interstellar clouds (approximately degree-sized on the sky and comprising 100 solar masses) and assessed the ratio of gas mass to dust mass. Significant variations of the gas/dust ratio are found both from cloud to cloud and within regions of indivi…
Resolving the Bright HCN(1-0) Emission toward the Seyfert 2 Nucleus of M51: Shock Enhancement by Radio Jets and Weak Masing by Infrared Pumping?
Matsushita, Satoki; Lim, Jeremy; Krips, Melanie +3 more
We present high angular resolution observations of the HCN(1-0) emission (at ~1'' or ~34 pc), together with CO J = 1-0, 2-1, and 3-2 observations, toward the Seyfert 2 nucleus of M51 (NGC 5194). The overall HCN(1-0) distribution and kinematics are very similar to that of the CO lines, which have been indicated as the jet-entrained molecular gas in…
Young Galaxy Candidates in the Hubble Frontier Fields. II. MACS J0416-2403
Broadhurst, Tom; Moustakas, John; Zheng, Wei +14 more
We searched for z ≳ 7 Lyman-break galaxies in the optical-to-mid-infrared Hubble Frontier Field and associated parallel field observations of the strong-lensing cluster MACS J0416-2403. We discovered 22 candidates, of which 6 lie at z ≳ 9 and 1 lies at z ≳ 10. Based on the Hubble and Spitzer photometry, all have secure photometric redshifts and a …
Exploring the Properties of Milliarcsecond Radio Sources
Cao, Shuo; Biesiada, Marek; Zhu, Zong-Hong +1 more
Cosmological applications of the “redshift—angular size” test require knowledge of the linear size of the “standard rod” used. In this paper, we study the properties of a large sample of 140 mas compact radio sources with flux densities measured at 6 and 20 cm, compiled by Gurvits et al. Using the best-fitted cosmological parameters given by Planc…
Rest-frame Optical Emission Lines in Far-infrared-selected Galaxies at z < 1.7 from the FMOS-COSMOS Survey
Daddi, E.; Riguccini, L.; Kartaltepe, Jeyhan S. +15 more
We have used FMOS on Subaru to obtain near-infrared spectroscopy of 123 far-infrared-selected galaxies in COSMOS and the key rest-frame optical emission lines. This is the largest sample of infrared galaxies with near-infrared spectroscopy at these redshifts. The far-infrared selection results in a sample of galaxies that are massive systems that …
The Survey of Lines in M31 (SLIM): Investigating the Origins of [C II] Emission
Fouesneau, M.; Walter, F.; Schinnerer, E. +7 more
The [C II] 158 µm line is one of the strongest emission lines observed in star-forming galaxies and has been empirically measured to correlate with the star-formation rate (SFR) globally and on kiloparsec scales. However, because of the multiphase origins of [C II], one might expect this relation to break down at small scales. We investigate…
NuSTAR Reveals Relativistic Reflection But No Ultra-Fast Outflow in the Quasar Pg∼1211+143
Harrison, F. A.; Craig, W.; Stern, D. +9 more
We report on four epochs of observations of the quasar PG 1211+143 using NuSTAR. The net exposure time is 300 ks. Prior work on this source found suggestive evidence of an ultra-fast outflow (UFO) in the Fe K band with a velocity of approximately 0.1c. The putative flow would carry away a high-mass flux and kinetic power, with broad implications f…
A Solar Coronal Jet Event Triggers a Coronal Mass Ejection
Wang, Yuming; Shen, Chenglong; Wang, S. +3 more
In this paper, we present multi-point, multi-wavelength observations and analysis of a solar coronal jet and coronal mass ejection (CME) event. Employing the GCS model, we obtained the real (three-dimensional) heliocentric distance and direction of the CME and found it to propagate at a high speed of over 1000 km s-1. The jet erupted be…