A5053114205- Astrophysics and Star Formation Studies
- Stellar, planetary, and galactic studies
- Galaxies: Formation, Evolution, Phenomena
- Astro and Planetary Science
- Astrophysics and Cosmic Phenomena
- Spectroscopy and Laser Applications
- Astronomy and Astrophysical Research
- Astronomical Observations and Instrumentation
- Particle Accelerators and Free-Electron Lasers
- Gamma-ray bursts and supernovae
- Radio Astronomy Observations and Technology
- Atmospheric Ozone and Climate
- Astrophysical Phenomena and Observations
- Particle accelerators and beam dynamics
- Atomic and Subatomic Physics Research
University of California, Los Angeles
2013-2021
Maria Mitchell Association
2013
University of Notre Dame
2012
We analyze the multifrequency behavior of quasar 3C 454.3 during three prominent \gamma-ray outbursts: 2009 Autumn, 2010 Spring, and Autumn. The data reveal a repeating pattern, including triple flare structure, in properties each outburst, which implies similar mechanism(s) location for all events. multi-frequency indicates that lower frequency events are co-spatial with outbursts, although emission varies on shortest timescales. determine variability from UV to IR wavelengths an outburst...
Abstract We present observations of CO(3–2) and 13 emission near the supernebula in dwarf galaxy NGC 5253, which contains one best examples a potential globular cluster formation. The 0.″3 resolution images reveal an unusual molecular cloud, “Cloud D1,” that is coincident with radio-infrared supernebula. ∼6 pc diameter cloud has linewidth, Δ v = 21.7 <?CDATA $\mathrm{km}\,{{\rm{s}}}^{-1}$?> , reflects only gravitational star residing within it. corresponding virial mass 2.5 × 10 5...
Abstract We observed Brackett α 4.05 μ m emission toward the supernebula in NGC 5253 with NIRSPEC on Keck II adaptive optics mode, NIRSPAO, to probe feedback from its exciting embedded super star cluster (SSC). NIRSPEC's Slit-viewing Camera was simultaneously used image K-band continuum at ∼0.″1 resolution. register IR HST imaging, and find that visible clusters are offset peak, which coincides Br peak of associated molecular cloud. The spectra exhibit a strong, narrow core. linewidths 65–76...
We report ALMA observations of $^{12}$CO(3-2) and $^{13}$CO(3-2) in the gas-poor dwarf galaxy NGC 5253. These 0.3"(5.5 pc) resolution images reveal small, dense molecular gas clouds that are located kinematically distinct, extended filaments. Some filaments appear to be falling into may fueling its current star formation. The most intense CO(3-2) emission comes from central $\sim$100 pc region centered on luminous radio-infrared HII known as supernebula. clumps within starburst...
We present subarcsecond images of submillimeter CO and continuum emission from a local galaxy forming massive star clusters: the blue compact dwarf II Zw 40. At $\sim$0.4" resolution (20 pc), CO(3-2), CO(1-0), 3mm 870${\mu}$m maps illustrate formation on scales individual molecular clouds. Dust contributes about third emission, with free-free accounting for rest. On these scales, there is not good correspondence between gas, dust, emission. enhanced toward star-forming region as compared to...
We present direct measures of the ionization fractions several sulfur ions in Galactic warm ionized medium (WIM). obtained high-resolution ultraviolet absorption-line spectroscopy post-asymptotic giant branch stars globular clusters Messier 3 [(l, b) = (422, +787), d 10.2 kpc, and z 10.0 kpc] 5 (39, +468), 7.5 +5.3 with Hubble Space Telescope Far Ultraviolet Spectroscopic Explorer to measure, or place limits on, column densities S i, ii, iii, iv, vi, H i. These also house millisecond...
We present ALMA CO(3-2) observations at 0.3 arcsec resolution of He2-10, a starburst dwarf galaxy and possible high-z analogue. The warm dense gas traced by CO(3--2) is found in clumpy filaments that are kinematically spatially distinct. have no preferred orientation or direction; this may indicate the not evolving into disk galaxy. Filaments appear to be feeding active starburst; velocity field one filament suggests acceleration onto an embedded star cluster. relative strengths radio...
We investigate the kinematics of ionized gas within nuclear starburst NGC 253 with observations Brackett $\alpha$ recombination line at 4.05 $\mu$m. The goal is to distinguish motions driven by star-formation feedback from gravitational induced central mass structure. Using NIRSPEC on Keck II, we obtained 30 spectra through a $0''.5$ slit stepped across $\sim$5$''\times 25''$ (85 $\times$ 425 pc) region produce spectral cube. Br$\alpha$ emission resolves into four sources: S1 infrared core...
ABSTRACT II Zw 40 is a starburst dwarf and merger product, holds radio-infrared supernebula excited by thousands of embedded OB stars. We present here observations three aspects the supernebula: maps K KU radio continuum that trace dense ionized gas with spatial resolution ${\sim} 0.1^{\prime \prime }$, spectral data cube [S iv]$10.5\,\mu$m emission line measures kinematics velocity 4.5 km s$^{-1}$, an ALMA (Atacama Large Millimeter Array) CO(3-2) probes warm molecular comparable to gas. The...
II Zw 40 is a starburst dwarf and merger product, holds radio-infrared supernebula excited by thousands of embedded OB stars. We present here observations three aspects the supernebula: maps K KU radio continuum that trace dense ionized gas with spatial resolution $\sim0.1^{\prime\prime}$, spectral data cube [S IV]$10.5\mu$m emission line measures kinematics velocity $4.5$ km s$^{-1}$, an ALMA CO(3-2) probes warm molecular comparable to gas. The suggest overlap,collision or two star...
The youngest, closest and most compact embedded massive star cluster known excites the supernebula in nearby dwarf galaxy NGC 5253. It is a crucial target test case for studying birth evolution of clusters. We present observations ionized gas this source with high spatial spectral resolution. data includes continuum images free-free emission ~0.15'' resolution made JVLA at 15, 22 33 GHz, full cube [SIV]10.5 micron fine-structure line ~4.5 km/s velocity 0.3'' beam, obtained TEXES on Gemini...
ABSTRACT We report Keck–NIRSPEC observations of the Brackett α 4.05 μm recombination line across two candidate embedded super star clusters (SSCs) in NGC 1569. These SSCs power a bright H ii region and have been previously detected as radio mid-infrared sources. Supplemented with high-resolution VLA mapping continuum along IRTF–TEXES spectroscopy [S iv] 10.5 line, data provide new insight into dynamical state gas ionized by these forming massive clusters. Near-infrared sources 2 images from...