Search Publications
A Population of Dust-rich Quasars at z ~ 1.5
Elvis, Martin; Willmer, Christopher N. A.; Magdis, Georgios E. +19 more
We report Herschel SPIRE (250, 350, and 500 µm) detections of 32 quasars with redshifts 0.5 <=z < 3.6 from the Herschel Multi-tiered Extragalactic Survey (HerMES). These sources are from a MIPS 24 µm flux-limited sample of 326 quasars in the Lockman Hole Field. The extensive multi-wavelength data available in the field permit con…
Star Formation History in Two Fields of the Small Magellanic Cloud Bar
Anderson, J.; Cignoni, M.; Tosi, M. +5 more
The Bar is the most productive region of the Small Magellanic Cloud in terms of star formation but also the least studied one. In this paper, we investigate the star formation history of two fields located in the SW and in the NE portion of the Bar using two independent and well-tested procedures applied to the color-magnitude diagrams of their st…
The Limit of Magnetic-shear Energy in Solar Active Regions
Moore, Ronald L.; Sterling, Alphonse C.; Falconer, David A.
It has been found previously, by measuring from active-region magnetograms a proxy of the free energy in the active region's magnetic field, (1) that there is a sharp upper limit to the free energy the field can hold that increases with the amount of magnetic field in the active region, the active region's magnetic flux content, and (2) that most …
The Remarkable High Pressure of the Local Leo Cold Cloud
Peek, J. E. G.; Heiles, Carl; Meyer, David M. +1 more
Using the Space Telescope Imaging Spectrograph (STIS) on board the Hubble Space Telescope, we have obtained high-resolution ultraviolet spectra of the C I absorption toward two stars behind the Local Leo Cold Cloud (LLCC). At a distance (≈20 pc) that places it well inside the Local Bubble, the LLCC is the nearest example of the coldest known (T ≈ …
Deep X-Ray Observations of the Young High-magnetic-field Radio Pulsar J1119-6127 and Supernova Remnant G292.2-0.5
Ng, C. -Y.; Shannon, R.; Weltevrede, P. +4 more
High-magnetic-field radio pulsars are important transition objects for understanding the connection between magnetars and conventional radio pulsars. We present a detailed study of the young radio pulsar J1119-6127, which has a characteristic age of 1900 yr and a spin-down-inferred magnetic field of 4.1 × 1013 G, and its associated supe…
Why is IGR J17091-3624 So Faint? Constraints on Distance, Mass, and Spin from "Phase-resolved" Spectroscopy of the "Heartbeat" Oscillations
Rao, Anjali; Vadawale, S. V.
IGR J17091-3624 is a transient X-ray source and is believed to be a Galactic black hole candidate. Recently, it has received considerable attention due to the detection of peculiar variability patterns known as "heartbeats," which are quasi-periodic mini-outbursts repeated over timescales ranging between 5 and 70 s. So far, such variability patter…
Measurements of the Sun's High-latitude Meridional Circulation
Hathaway, David H.; Rightmire-Upton, Lisa; Kosak, Katie
The meridional circulation at high latitudes is crucial to the buildup and reversal of the Sun's polar magnetic fields. Here, we characterize the axisymmetric flows by applying a magnetic feature cross-correlation procedure to high-resolution magnetograms obtained by the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observator…
Using the Bullet Cluster as a Gravitational Telescope to Study z >~ 7 Lyman Break Galaxies
Stiavelli, Massimo; Treu, Tommaso; Bradač, Maruša +7 more
We use imaging obtained with the Hubble Space Telescope Wide Field Camera 3 to search for z 850 dropouts at z ~ 7 and J 110 dropouts at z ~ 9 lensed by the Bullet Cluster. In total we find 10 z 850 dropouts in our 8.27 arcmin2 field. Using magnification maps from a combined weak- and strong-lensing mass …
Internal Structure of Protocluster Galaxies: Accelerated Structural Evolution in Overdense Environments?
Zirm, Andrew W.; Toft, Sune; Tanaka, Masayuki
We present a high spatial resolution Hubble Space Telescope/NICMOS imaging survey in the field of a known protocluster surrounding the powerful radio galaxy MRC1138-262 at z = 2.16. Previously, we have shown that this field exhibits a substantial surface overdensity of red J-H galaxies. Here we focus on the stellar masses and galaxy effective radi…
X-Ray Emission from the Wolf-Rayet Bubble S 308
Gruendl, R. A.; Smith, R. C.; Chu, Y. -H. +4 more
The Wolf-Rayet (WR) bubble S 308 around the WR star HD 50896 is one of the only two WR bubbles known to possess X-ray emission. We present XMM-Newton observations of three fields of this WR bubble that, in conjunction with an existing observation of its northwest quadrant, map most of the nebula. The X-ray emission from S 308 displays a limb-brigh…