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The Young Stellar Population, Distance, and Cloud-Cloud Collision Induced Star Formation Scenario of the Trifid Nebula
Kalari, Venu M.
The Trifid Nebula is a young, nearby star-forming region where star formation is proposed to have been triggered by cloud-cloud collision (CCC), based on observations of molecular clouds. It offers a unique opportunity to test whether the CCC hypothesis is supported by the spatial distribution and star formation chronology of young stars. We prese…
A VLA Survey of Late-time Radio Emission from Superluminous Supernovae and the Host Galaxies
Tamura, Yoichi; Tominaga, Nozomu; Hatsukade, Bunyo +5 more
We present the results of 3 GHz radio continuum observations of 23 superluminous supernovae (SLSNe) and their host galaxies by using the Karl G. Jansky Very Large Array conducted 5-21 yr after the explosions. The sample consists of 15 Type I and 8 Type II SLSNe at z < 0.3, providing one of the largest samples of SLSNe with late-time radio data.…
Tracking the Source of Solar Type II Bursts through Comparisons of Simulations and Radio Data
Kasper, Justin C.; Hegedus, Alexander M.; Manchester, Ward B.
The most intense solar energetic particle events are produced by coronal mass ejections (CMEs) accompanied by intense type II radio bursts below 15 MHz. Understanding where these type II bursts are generated relative to an erupting CME would reveal important details of particle acceleration near the Sun, but the emission cannot be imaged on Earth …
Possible Detection of X-Ray Emitting Circumstellar Material in the Synchrotron-dominated Supernova Remnant RX J1713.7-3946
Acero, Fabio; Katsuda, Satoru; Terada, Yukikatsu +4 more
We report on a discovery of an X-ray emitting circumstellar material (CSM) knot inside the synchrotron dominant supernova remnant RX J1713.7-3946. This knot was previously thought to be a Wolf-Rayet star (WR 85), but we realized that it is in fact ~40″ away from WR 85, indicating no relation to WR 85. We performed high-resolution X-ray spectroscop…
Disentangling the Physical Origin of Emission Line Ratio Offsets at High Redshift with Spatially Resolved Spectroscopy
Cooper, M. C.; Martin, Crystal L.; Treu, Tommaso +6 more
We present spatially resolved Hubble Space Telescope grism spectroscopy of 15 galaxies at z ~ 0.8 drawn from the DEEP2 survey. We analyze Hα+[N II], [S II], and [S III] emission on kiloparsec scales to explore which mechanisms are powering emission lines at high redshifts, testing which processes may be responsible for the well-known offset of hig…
Anomalous Hydrogen Recombination Line Ratios in Ultraluminous Infrared Galaxies
Nakagawa, Takao; Baba, Shunsuke; Isobe, Naoki +5 more
We conducted systematic observations of the H I Brα (4.05 µm) and Brβ (2.63 µm) lines in 52 nearby (z < 0.3) ultraluminous infrared galaxies (ULIRGs) with AKARI. Among 33 ULIRGs wherein the lines are detected, 3 galaxies show anomalous Brβ/Brα line ratios (~1.0), which are significantly higher than those for case B (0.565). Our obse…
Molecular Gas in the Nuclear Region of NGC 6240
Bally, John; Glenn, Jason; Rangwala, Naseem +3 more
NGC 6240 is a luminous infrared galaxy in the local universe in the midst of a major merger. We analyze high-resolution interferometric observations of warm molecular gas using CO J = 3-2 and 6-5 in the central few kpc of NGC 6240 taken by the Atacama Large Millimeter Array. Using these CO line observations, we model the density distribution and k…
Small-scale Bright Blobs Ejected from a Sunspot Light Bridge
Hou, Yijun; Chen, Yajie; Song, Yongliang +3 more
Light bridges (LBs) are bright lanes that divide an umbra into multiple parts in some sunspots. Persistent oscillatory bright fronts at a temperature of ∼105 K are commonly observed above LBs in the 1400/1330 Špassbands of the Interface Region Imaging Spectrograph (IRIS). Based on IRIS observations, we report small-scale bright blobs ej…
Spatial Distribution of O VI Covering Fractions in the Simulated Circumgalactic Medium
Charlton, Jane C.; Kacprzak, Glenn G.; Churchill, Christopher W. +6 more
We use adaptive mesh refinement cosmological simulations to study the spatial distribution and covering fraction of ${\rm{O}}\,{\rm\small{VI}}$ absorption in the circumgalactic medium (CGM) as a function of projected virial radius and azimuthal angle. We compare these simulations to an observed sample of 53 galaxies from the Multiphase Galaxy Halo…
Extremely Low Molecular Gas Content in the Vicinity of a Red Nugget Galaxy at z = 1.91
Stiavelli, M.; Lucas, R. A.; D'Amato, Q. +3 more
We present Atacama Large Millimeter/submillimeter Array Band 5 observations of a galaxy at z = 1.91, GDS24569, in search of molecular gas in its vicinity via the [C I] 3P1-3P0 line. GDS24569 is a massive ( $\mathrm{log}{M}_{* }/{M}_{\odot }=11$ ), passively evolving galaxy, characterized by compact morph…