Search Publications
Young Galaxy Candidates in the Hubble Frontier Fields. IV. MACS J1149.5+2223
Broadhurst, Tom; Moustakas, John; Zheng, Wei +11 more
We search for high-redshift dropout galaxies behind the Hubble Frontier Fields (HFF) galaxy cluster MACS J1149.5+2223, a powerful cosmic lens that has revealed a number of unique objects in its field. Using the deep images from the Hubble and Spitzer space telescopes, we find 11 galaxies at z > 7 in the MACS J1149.5+2223 cluster field, and 11 i…
Mass Profile Decomposition of the Frontier Fields Cluster MACS J0416-2403: Insights on the Dark-matter Inner Profile
Grillo, C.; Rosati, P.; Lombardi, M. +8 more
We present a high-resolution dissection of the two-dimensional total mass distribution in the core of the Hubble Frontier Fields galaxy cluster MACS J0416.1-2403, at z = 0.396. We exploit HST/WFC3 near-IR (F160W) imaging, VLT/Multi Unit Spectroscopic Explorer spectroscopy, and Chandra data to separate the stellar, hot gas, and dark-matter mass com…
Polycyclic Aromatic Hydrocarbon Emission in Spitzer/IRS Maps. II. A Direct Link between Band Profiles and the Radiation Field Strength
Peeters, E.; Stock, D. J.
We decompose the observed 7.7 µm polycyclic aromatic hydrocarbon (PAH) emission complexes in a large sample of over 7000 mid-infrared spectra of the interstellar medium using spectral cubes observed with the Spitzer/IRS-SL instrument. In order to fit the 7.7 µm PAH emission complex we invoke four Gaussian components, which are found to…
Probing the Anisotropy of the Milky Way Gaseous Halo-II: Sightline toward Mrk 509
Krongold, Y.; Mathur, S.; Gupta, A.
Hot, million degree gas appears to pervade the Milky Way halo, containing a large fraction of the Galactic missing baryons. This circumgalactic medium (CGM) is probed effectively in X-rays, both in absorption and in emission. The CGM also appears to be anisotropic, so we have started a program to determine CGM properties along several sightlines b…
The First Simultaneous X-Ray/Radio Detection of the First Be/BH System MWC 656
Iwasawa, K.; Migliari, S.; Marcote, B. +6 more
MWC 656 is the first known Be/black hole (BH) binary system. Be/BH binaries are important in the context of binary system evolution and sources of detectable gravitational waves because they are possible precursors of coalescing neutron star/BH binaries. X-ray observations conducted in 2013 revealed that MWC 656 is a quiescent high-mass X-ray bina…
A 13CO Detection in a Brightest Cluster Galaxy
Fabian, A. C.; Combes, F.; McDonald, M. +7 more
We present ALMA Cycle 4 observations of CO(1-0), CO(3-2), and 13CO(3-2) line emission in the brightest cluster galaxy (BCG) of RXJ0821+0752. This is one of the first detections of 13CO line emission in a galaxy cluster. Half of the CO(3-2) line emission originates from two clumps of molecular gas that are spatially offset fro…
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…