Search Publications
Suppressed CO emission and high G/D ratios in z = 2 galaxies with sub-solar gas-phase metallicity
Daddi, E.; Béthermin, M.; Sargent, M. T. +6 more
We study a population of significantly sub-solar enrichment galaxies at z = 1.99, to investigate how molecular gas, dust, and star formation relate in low-metallicity galaxies at the peak epoch of star formation. We target our sample with several deep Atacama Large Millimeter/submillimeter Array and Very Large Array datasets, and find no individua…
Coronal Plasma Characterization via Coordinated Infrared and Extreme Ultraviolet Observations of a Total Solar Eclipse
Del Zanna, Giulio; DeLuca, Edward E.; Samra, Jenna E. +1 more
We present coordinated coronal observations of the 2017 August 21 total solar eclipse with the Extreme-ultraviolet Imaging Spectrometer (EIS) and the Airborne Infrared Spectrometer (AIR-Spec). These instruments provide an unprecedented view of the solar corona in two disparate wavelength regimes, the extreme ultraviolet (EUV) and the near- to mid-…
Resolved Imaging of the AR Puppis Circumbinary Disk
Marshall, J. P.; Ertel, S.; Milli, J. +14 more
Circumbinary disks are common around post-asymptotic giant branch (post-AGB) stars with a stellar companion on orbital timescales of a few 100 to few 1000 days. The presence of a disk is usually inferred from the system’s spectral energy distribution and confirmed, for a sub-sample, by interferometric observations. We used the Spectro-Polarimetric…
Development of a Fast CME and Properties of a Related Interplanetary Transient
Grechnev, V. V.; Kochanov, A. A.; Kiselev, V. I. +5 more
We study the development of a coronal mass ejection (CME) caused by a prominence eruption on 24 February 2011 and properties of a related interplanetary CME (ICME). The prominence destabilized, accelerated, and produced an M3.5 flare, a fast CME, and a shock wave. The eruption at the east limb was observed in quadrature by the Atmospheric Imaging …
To be or not to be: the case of the hot WHIM absorption in the blazar PKS 2155-304 sight line
Finoguenov, A.; Kaastra, J.; Bonamente, M. +8 more
The cosmological missing baryons at z < 1 most likely hide in the hot (T ≳ 105.5 K) phase of the warm hot intergalactic medium (WHIM). While the hot WHIM is hard to detect due to its high ionisation level, the warm (T ≲ 105.5 K) phase of the WHIM has been very robustly detected in the far-ultraviolet (FUV) band. We adopted…
ALMA reveals a pseudo-disc in a proto-brown dwarf
Riaz, B.; Stamatellos, D.; Machida, M. N.
We present the observational evidence of a pseudo-disc around the proto-brown dwarf Mayrit 1701117, the driving source of the large-scale HH 1165 jet. Our analysis is based on Atacama Large Millimeter/submillimeter Array 12CO (2-1) line and 1.37 mm continuum observations at an angular resolution of ∼0.4 arcsec. The pseudo-disc is a brig…
A Hard Look at NGC 5347: Revealing a Nearby Compton-thick AGN
Kaastra, J. S.; Stern, D.; Brandt, W. N. +11 more
Current measurements show that the observed fraction of Compton-thick (CT) active galactic nuclei (AGN) is smaller than the expected values needed to explain the cosmic X-ray background. Prior fits to the X-ray spectrum of the nearby Seyfert-2 galaxy NGC 5347 (z = 0.00792, D = 35.5 Mpc ) have alternately suggested a CT and Compton-thin source. Com…
Spitzer Catalog of Herschel-selected Ultrared Dusty Star-forming Galaxies
Serjeant, Stephen; Dunne, Loretta; Ashby, Matthew L. N. +24 more
The largest Herschel extragalactic surveys, H-ATLAS and HerMES, have selected a sample of “ultrared” dusty star-forming galaxies (DSFGs) with rising SPIRE flux densities (S 500 > S 350 > S 250; the so-called “500 µm risers”) as an efficient way for identifying DSFGs at higher redshift (z > 4). In thi…
A Dissection of Spatially Resolved AGN Feedback across the Electromagnetic Spectrum
Koss, Michael; Mushotzky, Richard; Crenshaw, D. Michael +7 more
We present optical SuperNova Integral Field Spectrograph integral field spectroscopy, Hubble Space Telescope optical imaging, Chandra X-ray imaging, and Very Large Array radio interferometry of the merging galaxy 2MASX J04234080+0408017, which hosts a Seyfert 2 active galactic nucleus (AGN) at z = 0.046. Our observations reveal that radiatively dr…
Imprints of the first billion years: Lyman limit systems at z ∼ 5
Worseck, Gábor; Prochaska, J. Xavier; Murphy, Michael T. +3 more
Lyman limit systems (LLSs) trace the low-density circumgalactic medium and the most dense regions of the intergalactic medium, so their number density and evolution at high-redshift, just after reionization, are important to constrain. We present a survey for LLSs at high redshifts, zLLS = 3.5-5.4, in the homogeneous data set of 153 opt…