Search Publications
Chromospheric Condensation and Quasi-periodic Pulsations in a Circular-ribbon Flare
Li, D.; Zhang, Q. M.; Ning, Z. J.
In this paper, we report our multiwavelength observations of the C3.1 circular-ribbon flare SOL2015-10-16T10:20 in active region (AR) 12434. The flare consisted of a circular flare ribbon (CFR), an inner flare ribbon (IFR) inside it, and a pair of short parallel flare ribbons (PFRs). The PFRs located to the north of the IFR were most striking in t…
Infrared Spectral Energy Distribution Decomposition of WISE-selected, Hyperluminous Hot Dust-obscured Galaxies
Nikutta, Robert; Knudsen, Kirsten K.; Drouart, Guillaume +2 more
We utilize a Bayesian approach to fit the observed mid-IR-to-submillimeter/millimeter spectral energy distributions (SEDs) of 22 WISE-selected and submillimeter-detected, hyperluminous hot dust-obscured galaxies (Hot DOGs), with spectroscopic redshift ranging from 1.7 to 4.6. We compare the Bayesian evidence of a torus plusgraybody (Torus+GB) mode…
On the Metallicity and Origin of the Smith High-velocity Cloud
Sembach, Kenneth R.; Lockman, Felix J.; Rahman, Mubdi +7 more
The Smith Cloud (SC) is a gaseous high-velocity cloud (HVC) in an advanced state of accretion, only 2.9 kpc below the Galactic plane and due to impact the disk in ≈27 Myr. It is unique among HVCs in having a known distance (12.4 ± 1.3 kpc) and a well-constrained 3D velocity (296 km s-1), but its origin has long remained a mystery. Here …
First Gaia Local Group Dynamics: Magellanic Clouds Proper Motion and Rotation
van der Marel, Roeland P.; Sahlmann, Johannes
We use the Gaia data release 1 (DR1) to study the proper motion (PM) fields of the Large and Small Magellanic Clouds (LMC, SMC). This uses the Tycho-Gaia Astrometric Solution (TGAS) PMs for 29 Hipparcos stars in the LMC and 8 in the SMC. The LMC PM in the West and North directions is inferred to be ({µ }W,{µ }N) =…
Radio Disappearance of the Magnetar XTE J1810-197 and Continued X-ray Timing
Camilo, F.; Ransom, S. M.; Johnston, S. +6 more
We report on timing, flux density, and polarimetric observations of the transient magnetar and 5.54 s radio pulsar XTE J1810-197 using the Green Bank, Nançay, and Parkes radio telescopes beginning in early 2006, until its sudden disappearance as a radio source in late 2008. Repeated observations through 2016 have not detected radio pulsations agai…
Determining Ages of APOGEE Giants with Known Distances
Bovy, Jo; Majewski, Steven R.; Feuillet, Diane K. +4 more
We present a sample of 705 local giant stars observed using the New Mexico State University 1 m telescope with the Sloan Digital Sky Survey-III/Apache Point Observatory Galactic Evolution Experiment (APOGEE) spectrograph, for which we estimate stellar ages and the local star formation history (SFH). The high-resolution (R ∼ 22,500), near infrared …
SN Refsdal: Classification as a Luminous and Blue SN 1987A-like Type II Supernova
Zitrin, A.; Filippenko, A. V.; Foley, R. J. +20 more
We have acquired Hubble Space Telescope (HST) and Very Large Telescope near-infrared spectra and images of supernova (SN) Refsdal after its discovery as an Einstein cross in fall 2014. The HST light curve of SN Refsdal has a shape consistent with the distinctive, slowly rising light curves of SN 1987A-like SNe, and we find strong evidence for a br…
Origin of Molecular Oxygen in Comet 67P/Churyumov-Gerasimenko
Wurz, P.; Altwegg, K.; Bieler, A. +13 more
Molecular oxygen has been detected in the coma of comet 67P/Churyumov-Gerasimenko with abundances in the 1%-10% range by the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis-Double Focusing Mass Spectrometer instrument on board the Rosetta spacecraft. Here we find that the radiolysis of icy grains in low-density environments such as the p…
A Distant Echo of Milky Way Central Activity Closes the Galaxy’s Baryon Census
Elvis, M.; Nicastro, F.; Krongold, Y. +2 more
We report on the presence of large amounts of million-degree gas in the Milky Way’s interstellar and circum-galactic medium. This gas (1) permeates both the Galactic plane and the halo, (2) extends to distances larger than 60-200 kpc from the center, and (3) its mass is sufficient to close the Galaxy’s baryon census. Moreover, we show that a vast,…
The Wind Nebula around Magnetar Swift J1834.9-0846
Lin, L.; Kouveliotou, C.; Baring, M. G. +12 more
We report on the analysis of two deep XMM-Newton observations of the magnetar Swift J1834.9-0846 and its surrounding extended emission taken in 2014 March and October, 2.5 and 3.1 yr after the source went into outburst. The magnetar is only weakly detected in the first observation, with an absorption-corrected flux {F}0.5-10{keV}≈ 4× {1…