Search Publications
Modeling Extragalactic Foregrounds and Secondaries for Unbiased Estimation of Cosmological Parameters from Primary Cosmic Microwave Background Anisotropy
Doré, O.; Dudley, J.; Knox, L. +5 more
Using the latest physical modeling and constrained by the most recent data, we develop a phenomenological parameterized model of the contributions to intensity and polarization maps at millimeter wavelengths from external galaxies and Sunyaev-Zeldovich effects. We find such modeling to be necessary for estimation of cosmological parameters from Pl…
Characterizing CO Fourth Positive Emission in Young Circumstellar Disks
Herczeg, Gregory J.; Valenti, Jeff A.; Brown, Alexander +5 more
Carbon monoxide is a commonly used IR/submillimeter tracer of gas in protoplanetary disks. We present an analysis of ultraviolet CO emission in Hubble Space Telescope Cosmic Origins Spectrograph spectra for 12 Classical T Tauri stars (CTTSs). Several ro-vibrational bands of the CO A 1Π-X 1Σ+ (Fourth Positive) elect…
Cosmic Origins Spectrograph Observations of Warm Intervening Gas at z ~ 0.325 toward 3C 263
Savage, Blair D.; Wakker, Bart P.; Narayanan, Anand
We present HST/COS high-S/N observations of the z = 0.32566 multiphase absorber toward 3C 263. The Cosmic Origins Spectrograph (COS) data show absorption from H I (Lyα to Lyθ), O VI, C III, N III, Si III, and C II. The Ne VIII in this absorber is detected in the FUSE spectrum along with O III, O IV, and N IV. The low and intermediate ions are kine…
Revisiting the Chlorine Abundance in Diffuse Interstellar Clouds from Measurements with the Copernicus Satellite
Federman, S. R.; Sheffer, Y.; Moomey, Daniel
We reanalyzed interstellar Cl I and Cl II spectra acquired with the Copernicus satellite. The directions for this study come from those of Crenny & Federman and sample the transition from atomic to molecular-rich clouds where the unique chemistry leading to molecules containing chlorine is initiated. Our profile syntheses relied on up-to-date …
A Lighthouse Effect in Eta Carinae
Madura, Thomas I.; Groh, Jose H.
We present a new model for the behavior of scattered time-dependent, asymmetric near-UV emission from the nearby ejecta of η Car. Using a three-dimensional (3D) hydrodynamical simulation of η Car's binary colliding winds, we show that the 3D binary orientation derived by Madura et al. in 2012 is capable of explaining the asymmetric near-UV variabi…
AGN Activity and the Misaligned Hot ISM in the Compact Radio Elliptical NGC 4278
Trinchieri, Ginevra; Zezas, Andreas; Gallagher, John S. +5 more
The analysis of a deep (579 ks) Chandra ACIS pointing of the elliptical galaxy NGC 4278, which hosts a low-luminosity active galactic nucleus (AGN) and compact radio emission, allowed us to detect extended emission from hot gas out to a radius of ~5 kpc, with 0.5-8 keV luminosity of 2.4 × 1039 erg s-1. The emission is elongat…
Measuring Sizes of Ultra-faint Dwarf Galaxies
Geha, Marla; Padmanabhan, Nikhil; Muñoz, Ricardo R.
The discovery of ultra-faint dwarf (UFD) galaxies in the halo of the Milky Way extends the faint end of the galaxy luminosity function to a few hundred solar luminosities. This extremely low luminosity regime poses a significant challenge for the photometric characterization of these systems. We present a suite of simulations aimed at understandin…
The Quiescent X-Ray Properties of the Accreting Millisecond X-Ray Pulsar and Eclipsing binary Swift J1749.4-2807
Degenaar, N.; Wijnands, R.; Patruno, A.
Swift J1749.4-2807 is a transient neutron star low-mass X-ray binary that contains an accreting millisecond X-ray pulsar spinning at 518 Hz. It is the first of its kind that displays X-ray eclipses, which holds significant promise to precisely constrain the mass of the neutron star. We report on a ~= 105 ks long XMM-Newton observation performed wh…
A Flux-limited Sample of z ~ 1 Lyα Emitting Galaxies in the Chandra Deep Field South
Barger, A. J.; Cowie, L. L.; Wold, I. G. B.
We describe a method for obtaining a flux-limited sample of Lyα emitters from Galaxy Evolution Explorer (GALEX) grism data. We show that the multiple GALEX grism images can be converted into a three-dimensional (two spatial axes and one wavelength axis) data cube. The wavelength slices may then be treated as narrowband images and searched for emis…
Exploring the Relation between (Sub-)Millimeter Radiation and γ-Ray Emission in Blazars with Planck and Fermi
Lähteenmäki, A.; Polenta, G.; Gasparrini, D. +5 more
The coexistence of Planck and Fermi satellites in orbit has enabled the exploration of the connection between the (sub-)millimeter and γ-ray emission in a large sample of blazars. We find that the γ-ray emission and the (sub-)mm luminosities are correlated over five orders of magnitude, L γvpropL (sub-)mm. However, this corre…