Search Publications
CANDELS Sheds Light on the Environmental Quenching of Low-mass Galaxies
Papovich, Casey; Pérez-González, Pablo G.; Santini, Paola +17 more
We investigate the environmental quenching of galaxies, especially those with stellar masses (M *) < 109.5 M ⊙, beyond the local universe. Essentially all local low-mass quenched galaxies (QGs) are believed to live close to massive central galaxies, which is a demonstration of environmental quenching. We use CAN…
A Likely Redback Millisecond Pulsar Counterpart of 3FGL J0838.8-2829
Halpern, J. P.; Strader, J.; Li, M.
We obtained new optical observations of the X-ray source XMMU J083850.38-282756.8, the previously proposed counterpart of the γ-ray source 3FGL J0838.8-2829. Time-series photometry in the r\prime band reveals periodic modulation of ≈ 1 mag that is characteristic of the heating of the photosphere of a low-mass companion star by a compact…
High-energy Variability of PSR J1311-3430
An, Hongjun; Kerr, Matthew; Romani, Roger W. +2 more
We have studied the variability of the black-widow-type binary millisecond pulsar PSR J1311-3430 from optical to gamma-ray energies. We confirm evidence for orbital modulation in the weak off-pulse ≳200 MeV emission, with a peak at {φ }B≈ 0.8, following pulsar inferior conjunction. The peak has a relatively hard spectrum, extending abov…
Explosive Chromospheric Evaporation Driven by Nonthermal Electrons around One Footpoint of a Solar Flare Loop
Huang, Y.; Li, D.; Zhang, Q. M. +1 more
We explore the temporal relationship between microwave/hard X-ray (HXR) emission and Doppler velocity during the impulsive phase of a solar flare on 2014 October 27 (SOL2014-10-27) that displays a pulse on the light curves in the microwave (34 GHz) and HXR (25-50 keV) bands before the flare maximum. Imaging observation shows that this pulse mainly…
ALMA Observations of a Quiescent Molecular Cloud in the Large Magellanic Cloud
Rosolowsky, Erik; Hughes, Annie; Bernard, Jean-Philippe +19 more
We present high-resolution (subparsec) observations of a giant molecular cloud in the nearest star-forming galaxy, the Large Magellanic Cloud. ALMA Band 6 observations trace the bulk of the molecular gas in 12CO(2-1) and the high column density regions in 13CO(2-1). Our target is a quiescent cloud (PGCC G282.98-32.40, which w…
New Evidence for Charge-sign-dependent Modulation During the Solar Minimum of 2006 to 2009
Potgieter, M. S.; Vos, E. E.; Munini, R. +1 more
The PAMELA space experiment, in orbit since 2006, has measured cosmic rays (CRs) through the most recent period of minimum solar activity with the magnetic field polarity as A < 0. During this entire time, galactic electrons and protons have been detected down to 70 MV and 400 MV, respectively, and their differential variation in intensity with…
Microlensing Constraints on the Mass of Single Stars from HST Astrometric Measurements
Udalski, A.; Rejkuba, M.; Anderson, J. +13 more
We report on the first results from a large-scale observing campaign aiming to use astrometric microlensing to detect and place limits on the mass of single objects, including stellar remnants. We used the Hubble Space Telescope to monitor stars near the Galactic Center for three years, and we measured the brightness and positions of ∼2 million st…
Comparing Automatic CME Detections in Multiple LASCO and SECCHI Catalogs
Hess, Phillip; Colaninno, Robin C.
With the creation of numerous automatic detection algorithms, a number of different catalogs of coronal mass ejections (CMEs) spanning the entirety of the Solar and Heliospheric Observatory (SOHO) Large Angle Spectrometric Coronagraph (LASCO) mission have been created. Some of these catalogs have been further expanded for use on data from the Sola…
New Insights in the Mid-infrared Bubble N49 Site: A Clue of Collision of Filamentary Molecular Clouds
Dewangan, L. K.; Ojha, D. K.; Zinchenko, I.
We investigate the star formation processes operating in a mid-infrared bubble N49 site that harbors an O-type star in its interior, an ultracompact H II region, and a 6.7 GHz methanol maser at its edges. The 13CO line data reveal two velocity components (at velocity peaks ∼88 and ∼95 km s-1) in the direction of the bubble. A…
The Spectroscopy and H-band Imaging of Virgo Cluster Galaxies (SHIVir) Survey: Scaling Relations and the Stellar-to-total Mass Relation
Taylor, James E.; Holtzman, Jon A.; Cappellari, Michele +10 more
We present parameter distributions and fundamental scaling relations for 190 Virgo cluster galaxies in the SHIVir survey. The distribution of galaxy velocities is bimodal about V circ ∼ 125 km s-1, hinting at the existence of dynamically unstable modes in the inner regions of galaxies. An analysis of the Tully-Fisher relation…