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Magnesium-rich Ejecta in the SNR G284.3-1.8 Around the High-mass Gamma-Ray Binary 1FGL J1018.6-5856
Pavlov, George G.; Kargaltsev, Oleg; Rangelov, Blagoy +1 more
We present results from two Chandra observations of the 16.6 day X-ray/γ-ray high-mass binary 1FGL J1018.6-5856 located at the center of the supernova remnant (SNR) G284.3-1.8. The binary spectra, separated by 0.25 in binary phase, are fit with an absorbed power-law model with {{Γ }}≈ 1.7-1.8 for both observations (the flux during the second obser…
Two Populations of Old Star Clusters in the Spiral Galaxy M101 Based on HST/ACS Observations
Whitmore, Bradley C.; Chandar, Rupali; Simanton, Lesley A.
We present a new photometric catalog of 326 candidate globular clusters (GCs) in the nearby spiral galaxy M101, selected from B, V, and I Hubble Space Telescope Advanced Camera for Surveys images. The luminosity function (LF) of these clusters has an unusually large number of faint sources compared with GCLFs in many other spiral galaxies. Accordi…
The Atacama Cosmology Telescope: The LABOCA/ACT Survey of Clusters at All Redshifts
Hilton, Matt; Sifón, Cristóbal; Bond, J. Richard +24 more
We present a multi-wavelength analysis of 11 Sunyaev-Zel’dovich effect (SZE)-selected galaxy clusters (10 with new data) from the Atacama Cosmology Telescope (ACT) southern survey. We have obtained new imaging from the Large APEX Bolometer Camera (345 GHz; LABOCA) on the Atacama Pathfinder EXperiment (APEX) telescope, the Australia Telescope Compa…
RCS2 J232727.6-020437: An Efficient Cosmic Telescope at z=0.6986
Sharon, K.; Schrabback, T.; Hoag, A. +13 more
We present a detailed gravitational lens model of the galaxy cluster RCS2 J232727.6-020437. Due to cosmological dimming of cluster members and intra-cluster light, its high redshift (z = 0.6986) makes it ideal for studying high-redshift background galaxies. Using new Advanced Camera for Surveys and WFC3/IR Hubble Space Telescope data, we identify …
Rethinking a Mysterious Molecular Cloud
Imara, N.
I present high-resolution column density maps of two molecular clouds (MCs) having strikingly different star formation rates. To better understand the unusual, massive G216-2.5, an MC with no massive star formation, the distribution of its molecular gas is compared to that of the Rosette MC. Far-infrared data from Herschel are used to derive N(H
Updated 24 µm Period-Luminosity Relation Derived from Galactic Cepheids
Ngeow, Chow-Choong; Kanbur, Shashi M.; Bhardwaj, Anupam +2 more
In this work, we updated the catalog of Galactic Cepheids with 24 µm photometry by cross-matching the positions of known Galactic Cepheids to the recently released MIPSGAL point source catalog. We have added 36 new sources featuring MIPSGAL photometry in our analysis, thus increasing the existing sample to 65. Six different sources of compil…
Spectral Imaging of Galaxy Clusters with Planck
Rasia, E.; Bourdin, H.; Mazzotta, P.
The Sunyaev-Zeldovich (SZ) effect is a promising tool for detecting the presence of hot gas out to the galaxy cluster peripheries. We developed a spectral imaging algorithm dedicated to the SZ observations of nearby galaxy clusters with Planck, with the aim of revealing gas density anisotropies related to the filamentary accretion of materials, or…
A Coordinated X-Ray and Optical Campaign of the Nearest Massive Eclipsing Binary, δ Orionis Aa. I. Overview of the X-Ray Spectrum
Gull, T. R.; Corcoran, M. F.; Owocki, S. P. +22 more
We present an overview of four deep phase-constrained Chandra HETGS X-ray observations of δ Ori A. Delta Ori A is actually a triple system that includes the nearest massive eclipsing spectroscopic binary, δ Ori Aa, the only such object that can be observed with little phase-smearing with the Chandra gratings. Since the fainter star, δ Ori Aa2, has…
NGC 1266: Characterization of the Nuclear Molecular Gas in an Unusual SB0 Galaxy
Glenn, J.; Maloney, P. R.; Rangwala, N. +1 more
With a substantial nuclear molecular gas reservoir and broad, high-velocity CO molecular line wings previously interpreted as an outflow, NGC 1266 is a rare SB0 galaxy. Previous analyses of interferometry, spectrally resolved low-J CO emission lines, and unresolved high-J emission lines have established basic properties of the molecular gas and th…
Relative Abundance Measurements in Plumes and Interplumes
Hahn, M.; Savin, D. W.; Guennou, C.
We present measurements of relative elemental abundances in plumes and interplumes. Plumes are bright, narrow structures in coronal holes that extend along open magnetic field lines far out into the corona. Previous work has found that in some coronal structures the abundances of elements with a low first ionization potential (FIP) <10 eV are e…