Search Publications
A New Challenge to Solar Dynamo Models from Helioseismic Observations: The Latitudinal Dependence of the Progression of the Solar Cycle
Hill, F.; Jain, K.; Tripathy, S. C. +1 more
The onset of the solar cycle at mid-latitudes, the slowdown in the drift of sunspots toward the equator, the tail-like attachment, and the overlap of successive cycles at the time of minimum activity are delicate issues in models of the αΩ dynamo wave and the flux transport dynamo. Very different parameter values produce similar results, making it…
A Search for O2 in CO-depleted Molecular Cloud Cores with Herschel
Ceccarelli, Cecilia; Charnley, Steven B.; Cordiner, Martin A. +1 more
The general lack of molecular oxygen in molecular clouds is an outstanding problem in astrochemistry. Extensive searches with the Submillimeter Astronomical Satellite, Odin, and Herschel have only produced two detections; upper limits to the O2 abundance in the remaining sources observed are about 1000 times lower than predicted by chem…
Radial Distribution of ISM Gas-phase Metallicity in CLASH Clusters at z ~ 0.35: A New Outlook on Environmental Impact on Galaxy Evolution
Kewley, Lisa J.; Tran, Kim-Vy H.; Gupta, Anshu +3 more
We present the first observation of cluster-scale radial metallicity gradients from star-forming galaxies. We use DEIMOS on the Keck II telescope to observe two CLASH clusters at z ∼ 0.35: MACS J1115+0129 and RX J1532+3021. Based on our measured interstellar medium properties of star-forming galaxies out to a radius of 2.5 Mpc from the cluster cen…
The 6 µm Feature As a Tracer of Aliphatic Components of Interstellar Carbonaceous Grains
Zhang, Yong; Kwok, Sun; Hsia, Chih-Hao +1 more
An unidentified infrared emission (UIE) feature at 6.0 µm is detected in a number of astronomical sources showing the UIE bands. In contrast to the previous suggestion that this band is due to C=O vibrational modes, we suggest that the 6.0 µm feature arises from olefinic double-bond functional groups. These groups are likely to be atta…
The Circumgalactic Medium of Submillimeter Galaxies. I. First Results from a Radio-identified Sample
Cooray, A.; Fu, Hai; Michałowski, M. J. +14 more
We present the first results from an ongoing survey to characterize the circumgalactic medium (CGM) of massive high-redshift galaxies detected as submillimeter galaxies (SMGs). We constructed a parent sample of 163 SMG-QSO pairs with separations less than ∼36″ by cross-matching far-infrared-selected galaxies from Herschel with spectroscopically co…
Herschel Observations and Updated Spectral Energy Distributions of Five Sunlike Stars with Debris Disks
Green, Joel D.; Su, Kate Y. L.; Bryden, Geoff +2 more
Observations from the Herschel Space Observatory have more than doubled the number of wide debris disks orbiting Sunlike stars to include over 30 systems with R > 100 AU. Here, we present new Herschel PACS and reanalyzed Spitzer MIPS photometry of five Sunlike stars with wide debris disks, from Kuiper Belt size to R > 150 AU. The disk surrou…
The Interplanetary Network Response to LIGO GW150914
Zhang, X.; Cline, T.; Hurley, K. +15 more
We have performed a blind search for a gamma-ray transient of arbitrary duration and energy spectrum around the time of the LIGO gravitational-wave event GW150914 with the six-spacecraft interplanetary network (IPN). Four gamma-ray bursts were detected between 30 hr prior to the event and 6.1 hr after it, but none could convincingly be associated …
Suzaku Observation of the High-inclination Binary EXO 0748-676 in the Hard State
Makishima, Kazuo; Nakazawa, Kazuhiro; Xu, Haiguang +4 more
Utilizing archived Suzaku data acquired on 2007 December 25 for 46 ks, the X-ray spectroscopic properties of the dipping and eclipsing low-mass X-ray binary EXO 0748-676 were studied. At an assumed distance of 7.1 kpc, the data provided a persistent unabsorbed luminosity of 3.4× {10}36 erg cm-2 s-1 in 0.6-55 keV. T…
Protostars at Low Extinction in Orion A
Lada, Charles J.; Lewis, John Arban
In the list of young stellar objects (YSOs) compiled by Megeath et al. for the Orion A molecular cloud, only 44 out of 1208 sources found projected onto low extinction ({A}{{K}}\lt 0.8 mag) gas are identified as protostars. These objects are puzzling because protostars are not typically expected to be associated with extended low extinc…
On the Host Galaxy of GRB 150101B and the Associated Active Galactic Nucleus
Liu, Tong; Wang, Junfeng; Fang, Taotao +2 more
We present a multi-wavelength analysis of the host galaxy of short-duration gamma-ray burst (GRB) 150101B. Follow-up optical and X-ray observations suggested that the host galaxy, 2MASX J12320498-1056010, likely harbors low-luminosity active galactic nuclei (AGNs). Our modeling of the spectral energy distribution has confirmed the nature of the AG…