Search Publications
A census of dense cores in the Taurus L1495 cloud from the Herschel
White, G. J.; André, Ph.; Könyves, V. +17 more
We present a catalogue of dense cores in a ∼4° × 2° field of the Taurus star-forming region, inclusive of the L1495 cloud, derived from Herschel SPIRE and PACS observations in the 70 µm, 160 µm, 250 µm, 350 µm, and 500 µm continuum bands. Estimates of mean dust temperature and total mass are derived using modified bla…
A New Population of Compton-thick AGNs Identified Using the Spectral Curvature above 10 keV
Harrison, F. A.; Stern, D.; Alexander, D. M. +19 more
We present a new metric that uses the spectral curvature (SC) above 10 keV to identify Compton-thick active galactic nuclei (AGNs) in low-quality Swift/Burst Alert Telescope (BAT) X-ray data. Using NuSTAR, we observe nine high SC-selected AGNs. We find that high-sensitivity spectra show that the majority are Compton-thick (78% or 7/9) and the rema…
Globular Clusters Indicate That Ultra-diffuse Galaxies Are Dwarfs
Beasley, Michael A.; Trujillo, Ignacio
We present an analysis of archival HST/ACS imaging in the F475W (g 475), F606W (V 606), and F814W (I 814) bands of the globular cluster (GC) system of a large (3.4 kpc effective radius) ultra-diffuse galaxy (DF17) believed to be located in the Coma Cluster of galaxies. We detect 11 GCs down to the 5σ completeness l…
A Universal Density Structure for Circumgalactic Gas
Stern, Jonathan; Hennawi, Joseph F.; Prochaska, J. Xavier +1 more
We develop a new method to constrain the physical conditions in the cool (∼104 K) circumgalactic medium (CGM) from measurements of ionic column densities by assuming that the cool CGM spans a large range of gas densities and that small high-density clouds are hierarchically embedded in large low-density clouds. The new method combines t…
Regulation of black-hole accretion by a disk wind during a violent outburst of V404 Cygni
Ponti, G.; Charles, P. A.; Rodriguez, J. +7 more
Accretion of matter onto black holes is universally associated with strong radiative feedback and powerful outflows. In particular, black-hole transients have outflows whose properties are strongly coupled to those of the accretion flow. This includes X-ray winds of ionized material, expelled from the accretion disk encircling the black hole, and …
Balloon-Borne Submillimeter Polarimetry of the Vela C Molecular Cloud: Systematic Dependence of Polarization Fraction on Column Density and Local Polarization-Angle Dispersion
Ward-Thompson, Derek; Fissel, Laura M.; Nakamura, Fumitaka +27 more
We present results for Vela C obtained during the 2012 flight of the Balloon-borne Large Aperture Submillimeter Telescope for Polarimetry. We mapped polarized intensity across almost the entire extent of this giant molecular cloud, in bands centered at 250, 350, and 500 µm. In this initial paper, we show our 500 µm data smoothed to a r…
Spectacular tails of ionized gas in the Virgo cluster galaxy NGC 4569
Ferrarese, L.; Boselli, A.; Cortese, L. +14 more
Context. Using MegaCam at the CFHT, we obtained a deep narrow band Hα+[NII] wide-field image of NGC 4569 (M90), the brightest late-type galaxy in the Virgo cluster. The image reveals the presence of long tails of diffuse ionized gas, without any associated stellar component extending from the disc of the galaxy up to ≃80 kpc (projected distance) a…
CMB constraints on cosmic strings and superstrings
Moss, Adam; Charnock, Tom; Avgoustidis, Anastasios +1 more
We present the first complete Markov chain Monte Carlo analysis of cosmological models with evolving cosmic (super)string networks, using the unconnected segment model in the unequal-time correlator formalism. For ordinary cosmic string networks, we derive joint constraints on Λ cold dark matter (CDM) and string network parameters, namely the stri…
Planck 2015 results. VII. High Frequency Instrument data processing: Time-ordered information and beams
Kneissl, R.; Miville-Deschênes, M. -A.; Boulanger, F. +225 more
The Planck High Frequency Instrument (HFI) has observed the full sky at six frequencies (100, 143, 217, 353, 545, and 857 GHz) in intensity and at four frequencies in linear polarization (100, 143, 217, and 353 GHz). In order to obtain sky maps, the time-ordered information (TOI) containing the detector and pointing samples must be processed and t…
The IBIS Soft Gamma-Ray Sky after 1000 Integral Orbits
Hill, A. B.; Bird, A. J.; Fiocchi, M. +6 more
Here we report an all-sky soft gamma-ray source catalog based on IBIS observations performed during the first 1000 orbits of INTEGRAL. The database for the construction of the source list consists of all good-quality data available, from the launch in 2002, up to the end of 2010. This corresponds to ∼110 Ms of scientific public observations, with …