Search Publications
Gas Emissions in Planck Cold Dust Clumps—A Survey of the J = 1-0 Transitions of 12CO, 13CO, and C18O
Li, Di; Liu, Tie; Qin, Sheng-Li +3 more
A survey toward 674 Planck cold clumps of the Early Cold Core Catalogue (ECC) in the J = 1-0 transitions of 12CO, 13CO, and C18O has been carried out using the Purple Mountain Observatory 13.7 m telescope. Six hundred seventy-three clumps were detected with 12CO and 13CO emission, and 68% of t…
Non-neutralized Electric Current Patterns in Solar Active Regions: Origin of the Shear-generating Lorentz Force
Mikić, Zoran; Georgoulis, Manolis K.; Titov, Viacheslav S.
Using solar vector magnetograms of the highest available spatial resolution and signal-to-noise ratio, we perform a detailed study of electric current patterns in two solar active regions (ARs): a flaring/eruptive and a flare-quiet one. We aim to determine whether ARs inject non-neutralized (net) electric currents in the solar atmosphere, respondi…
Distance and Kinematics of the Red Hypergiant VY CMa: Very Long Baseline Array and Very Large Array Astrometry
Menten, K. M.; Zhang, B.; Reid, M. J. +1 more
We report astrometric results of phase-referencing very long baseline interferometry observations of 43 GHz SiO maser emission toward the red hypergiant VY Canis Majoris (VY CMa) using the Very Long Baseline Array (VLBA). We measured a trigonometric parallax of 0.83 ± 0.08 mas, corresponding to a distance of 1.20+0.13 -0.10 k…
Photoevaporating Proplyd-like Objects in Cygnus OB2
Drake, Jeremy J.; Gutermuth, Robert A.; Wright, Nicholas J. +4 more
We report the discovery of 10 proplyd-like objects in the vicinity of the massive OB association Cygnus OB2. They were discovered in IPHAS Hα images and are clearly resolved in broadband Hubble Space Telescope/Advanced Camera for Surveys, near-IR, and Spitzer mid-IR images. All exhibit the familiar tadpole shape seen in photoevaporating objects su…
A Detection of Weak-lensing Magnification Using Galaxy Sizes and Magnitudes
Koekemoer, Anton M.; Leauthaud, Alexie; Massey, Richard +5 more
Weak lensing is commonly measured using shear through galaxy ellipticities or using the effect of magnification bias on galaxy number densities. Here, we report on the first detection of weak-lensing magnification with a new, independent technique using the distribution of galaxy sizes and magnitudes. These data come for free in galaxy surveys des…
PHAT Stellar Cluster Survey. I. Year 1 Catalog and Integrated Photometry
Monachesi, Antonela; Gouliermis, Dimitrios A.; Dolphin, Andrew E. +21 more
The Panchromatic Hubble Andromeda Treasury (PHAT) survey is an ongoing Hubble Space Telescope (HST) multi-cycle program to obtain high spatial resolution imaging of one-third of the M31 disk at ultraviolet through near-infrared wavelengths. In this paper, we present the first installment of the PHAT stellar cluster catalog. When completed, the PHA…
Revision of Solar Spicule Classification
Liu, Y.; Su, J. T.; Wang, J. X. +4 more
Solar spicules are the fundamental magnetic structures in the chromosphere and may play a key role in channeling the chromosphere and corona. Recently, it was suggested by De Pontieu et al. that there were two types of spicules with very different dynamic properties, which were detected by the space-time plot technique in the Ca II H line (3968 Å)…
Clustering Properties of BzK-selected Galaxies in GOODS-N: Environmental Quenching and Triggering of Star Formation at z ~ 2
Dickinson, Mark; Grogin, Norman A.; Yan, Chi-Hung +19 more
Using a sample of BzK-selected galaxies at z ~ 2 identified from the CFHT/WIRCAM near-infrared survey of GOODS-North, we discuss the relation between star formation rate (SFR), specific star formation rate (SSFR), and stellar mass (M *), and the clustering of galaxies as a function of these parameters. For star-forming galaxies (sBzKs),…
Automatically Detecting and Tracking Coronal Mass Ejections. I. Separation of Dynamic and Quiescent Components in Coronagraph Images
Morgan, Huw; Habbal, Shadia Rifai; Byrne, Jason P.
Automated techniques for detecting and tracking coronal mass ejections (CMEs) in coronagraph data are of ever increasing importance for space weather monitoring and forecasting. They serve to remove the biases and tedium of human interpretation, and provide the robust analysis necessary for statistical studies across large numbers of observations.…
Broad-line Region Physical Conditions in Extreme Population A Quasars: A Method to Estimate Central Black Hole Mass at High Redshift
Sulentic, Jack W.; Marziani, Paola; Negrete, C. Alenka +1 more
We describe a method for estimating physical conditions in the broad-line region (BLR) for a significant subsample of Seyfert 1 nuclei and quasars. Several diagnostic ratios based on intermediate (Al III λ1860, Si III] λ1892) and high (C IV λ1549, Si IV λ1397) ionization lines in the UV spectra of quasars are used to constrain density, ionization,…