Search Publications
Searching for Interstellar {{\rm{C}}}_{60}^{+} Using a New Method for High Signal-to-noise HST/STIS Spectroscopy
Gull, T. R.; Lallement, R.; Najarro, F. +9 more
Due to recent advances in laboratory spectroscopy, the first optical detection of a very large molecule has been claimed in the diffuse interstellar medium (ISM): {{{C}}}60+ (ionized Buckminsterfullerene). Confirming the presence of this molecule would have significant implications regarding the carbon budget and chemical com…
Current and Future Constraints on Primordial Magnetic Fields
Feng, Chang; Reichardt, Christian L.; Sutton, Dylan R.
We present new limits on the amplitude of potential primordial magnetic fields (PMFs) using temperature and polarization measurements of the cosmic microwave background (CMB) from Planck, the BICEP2/Keck Array, Polarbear, and SPTpol. We reduce twofold the 95% confidence upper limit on the CMB anisotropy power due to a nearly scale-invariant PMF, w…
Spectroscopic Observations of Magnetic Reconnection and Chromospheric Evaporation in an X-shaped Solar Flare
Gan, W. Q.; Ding, M. D.; Li, Y. +3 more
We present observations of distinct UV spectral properties at different locations during an atypical X-shaped flare (SOL2014-11-09T15:32) observed by the Interface Region Imaging Spectrograph (IRIS). In this flare, four chromospheric ribbons appear and converge at an X-point where a separator is anchored. Above the X-point, two sets of non-coplana…
The Origins of UV-optical Color Gradients in Star-forming Galaxies at z ∼ 2: Predominant Dust Gradients but Negligible sSFR Gradients
Barro, Guillermo; Faber, S. M.; Tacchella, Sandro +13 more
The rest-frame UV-optical (I.e., NUV - B) color is sensitive to both low-level recent star formation (specific star formation rate—sSFR) and dust. In this Letter, we extend our previous work on the origins of NUV - B color gradients in star-forming galaxies (SFGs) at z∼ 1 to those at z∼ 2. We use a sample of 1335 large (semimajor axis radius {R}
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…