Search Publications
The Dense Molecular Gas and Nuclear Activity in the ULIRG IRAS 13120-5453
Treister, E.; Armus, L.; van der Werf, P. +12 more
We present new Atacama Large Millimeter/submillimeter Array Band 7 (∼340 GHz) observations of the dense gas tracers HCN, HCO+, and CS in the local, single-nucleus, ultraluminous infrared galaxy IRAS 13120-5453. We find centrally enhanced HCN (4-3) emission, relative to HCO+ (4-3), but do not find evidence for radiative pumpin…
Hard X-Ray-selected AGNs in Low-mass Galaxies from the NuSTAR Serendipitous Survey
Harrison, F. A.; Stern, D.; Alexander, D. M. +14 more
We present a sample of 10 low-mass active galactic nuclei (AGNs) selected from the 40-month Nuclear Spectroscopic Telescope Array (NuSTAR) serendipitous survey. The sample is selected to have robust NuSTAR detections at 3{--}24 {keV}, to be at z< 0.3, and to have optical r-band magnitudes at least 0.5 mag fainter than an {L}\star ga…
The Plasma Parameters and Geometry of Cool and Warm Active Region Loops
Fu, Hui; Madjarska, Maria S.; Li, Bo +5 more
How the solar corona is heated to high temperatures remains an unsolved mystery in solar physics. In the present study we analyze observations of 50 whole active region loops taken with the Extreme-ultraviolet Imaging Spectrometer on board the Hinode satellite. Eleven loops were classified as cool loops (<1 MK) and 39 as warm loops (1-2 MK). We…
Massive Star Cluster Formation and Destruction in Luminous Infrared Galaxies in GOALS
Kim, D. -C.; Surace, J. A.; Inami, H. +17 more
We present the results of a Hubble Space Telescope ACS/HRC FUV, ACS/WFC optical study into the cluster populations of a sample of 22 Luminous Infrared Galaxies in the Great Observatories All-Sky LIRG Survey. Through integrated broadband photometry, we have derived ages and masses for a total of 484 star clusters contained within these systems. Thi…
X-Ray and Optical Study of the Gamma-ray Source 3FGL J0838.8-2829: Identification of a Candidate Millisecond Pulsar Binary and an Asynchronous Polar
Thorstensen, John R.; Bogdanov, Slavko; Halpern, Jules P.
We observed the field of the Fermi source 3FGL J0838.8-2829 in optical and X-rays, initially motivated by the cataclysmic variable (CV) 1RXS J083842.1-282723 that lies within its error circle. Several X-ray sources first classified as CVs have turned out to be γ-ray emitting millisecond pulsars (MSPs). We find that 1RXS J083842.1-282723 is in fact…
A Black Hole Mass Determination for the Compact Galaxy Mrk 1216
Gebhardt, Karl; Richstone, Douglas O.; Husemann, Bernd +4 more
Mrk 1216 is a nearby, early-type galaxy with a small effective radius of 2.8 kpc and a large stellar velocity dispersion of 308 km s-1 for its K-band luminosity of 1.4× {10}11 {L}⊙ . Using integral field spectroscopy assisted by adaptive optics from Gemini North, we measure spatially resolved stellar kinematics wit…
Successive Homologous Coronal Mass Ejections Driven by Shearing and Converging Motions in Solar Active Region NOAA 12371
Vemareddy, P.
We study the magnetic field evolution in AR 12371, related to its successive eruptive nature. During the disk transit of seven days, the active region (AR) launched four sequential fast coronal mass ejections (CMEs), which are associated with long duration M-class flares. Morphological study delineates a pre-eruptive coronal sigmoid structure abov…
The Role of the Most Luminous Obscured AGNs in Galaxy Assembly at z ∼ 2
Tsai, Chao-Wei; Moustakas, Leonidas; Stern, Daniel +14 more
We present Hubble Space Telescope WFC3 F160W imaging and infrared spectral energy distributions for 12 extremely luminous, obscured active galactic nuclei (AGNs) at 1.8 < z < 2.7 selected via “hot, dust-obscured” mid-infrared colors. Their infrared luminosities span (2-15) × 1013 L ⊙, making them among the most luminous…
Variability of the Magnetic Field Power Spectrum in the Solar Wind at Electron Scales
Escoubet, C. P.; Alexandrova, O.; Turc, L. +4 more
At electron scales, the power spectrum of solar-wind magnetic fluctuations can be highly variable and the dissipation mechanisms of the magnetic energy into the various particle species is under debate. In this paper, we investigate data from the Cluster mission’s STAFF Search Coil magnetometer when the level of turbulence is sufficiently high tha…
On the Link between the Release of Solar Energetic Particles Measured at Widespread Heliolongitudes and the Properties of the Associated Coronal Shocks
Lario, D.; Kwon, R. -Y.; Riley, P. +1 more
Under the paradigm that the main agents in the acceleration of solar energetic particles (SEPs) are shocks initially driven by coronal mass ejections, we analyze whether the properties of the shocks in the corona inferred from combining extreme-ultraviolet (EUV) and white-light (WL) observations from multiple vantage points together with magnetohy…