Search Publications
The SP_PREP Data Preparation Package for the Hinode Spectro-Polarimeter
Lites, B. W.; Ichimoto, K.
The Hinode/Spectro-Polarimeter (SP) is the first space-borne precision spectro-polarimeter for the study of solar phenomena. It is primarily intended for measuring the solar photospheric vector magnetic field at high spatial and spectral resolution. This objective requires that the data are calibrated and conditioned to a high degree of precision.…
Evidence for a Snow Line beyond the Transitional Radius in the TW Hya Protoplanetary Disk
Pontoppidan, K. M.; Blake, G. A.; Zhang, K. +1 more
We present an observational reconstruction of the radial water vapor content near the surface of the TW Hya transitional protoplanetary disk, and report the first localization of the snow line during this phase of disk evolution. The observations are comprised of Spitzer-IRS, Herschel-PACS, and Herschel-HIFI archival spectra. The abundance structu…
OGLE-2002-BLG-360: from a gravitational microlensing candidate to an overlooked red transient
Soszyński, I.; Udalski, A.; Szymański, M. K. +9 more
Context. OGLE-2002-BLG-360 was discovered as a microlensing candidate by the OGLE-III project. The subsequent light curve, however, clearly showed that the brightening of the object could not have resulted from the gravitational microlensing phenomenon.
Aims: We aim to explain the nature of OGLE-2002-BLG-360 and its eruption observed in 2002-…
A simplified view of blazars: the γ-ray case
Polenta, G.; Giommi, P.; Padovani, P.
We have recently proposed a new simplified scenario where blazars are classified as flat spectrum radio quasars (FSRQs) or BL Lacs according to the prescriptions of unified schemes, and to a varying combination of Doppler-boosted radiation from the jet, emission from the accretion disc, the broad line region and light from the host galaxy. Here we…
Evidence for Elevated X-Ray Emission in Local Lyman Break Galaxy Analogs
Heckman, Timothy M.; Hornschemeier, Ann E.; Schiminovich, David +6 more
Our knowledge of how X-ray emission scales with star formation at the earliest times in the universe relies on studies of very distant Lyman break galaxies (LBGs). In this paper, we study the relationship between the 2-10 keV X-ray luminosity (L X), assumed to originate from X-ray binaries (XRBs), and star formation rate (SFR) in ultrav…
Bifurcated Structure of the Electron Diffusion Region in Three-Dimensional Magnetic Reconnection
Li, H.; Daughton, W.; Karimabadi, H. +2 more
Three-dimensional kinetic simulations of magnetic reconnection reveal that the electron diffusion region is composed of two or more current sheets in regimes with weak magnetic shear angles ϕ≲80°. This new morphology is explained by oblique tearing modes which produce flux ropes while simultaneously driving enhanced current at multiple resonance s…
The HST/ACS+WFC3 Survey for Lyman Limit Systems. II. Science
Prochaska, J. Xavier; Chen, Hsiao-Wen; Madau, Piero +2 more
We present the first science results from our Hubble Space Telescope survey for Lyman limit absorption systems (LLS) using the low dispersion spectroscopic modes of the Advanced Camera for Surveys and the Wide Field Camera 3. Through an analysis of 71 quasars, we determine the incidence frequency of LLS per unit redshift and per unit path length, …
The D/H ratio in the atmospheres of Uranus and Neptune from Herschel-PACS observations
Hartogh, P.; Lellouch, E.; de Graauw, T. +9 more
Herschel-PACS measurements of the rotational R(0) and R(1) HD lines in the atmospheres of Uranus and Neptune are analyzed to derive a D/H ratio with improved precision for the two planets. The derivation of the D/H ratio also includes previous measurements of the R(2) line with the Short Wavelength Spectrometer on board the Infrared Space Observat…
Phibss: Molecular Gas, Extinction, Star Formation, and Kinematics in the z = 1.5 Star-forming Galaxy EGS13011166
Nordon, R.; Lutz, D.; Wuyts, S. +23 more
We report matched resolution imaging spectroscopy of the CO 3-2 line (with the IRAM Plateau de Bure millimeter interferometer) and of the Hα line (with LUCI at the Large Binocular Telescope) in the massive z = 1.53 main-sequence galaxy EGS 13011166, as part of the "Plateau de Bure high-z, blue-sequence survey" (PHIBSS: Tacconi et al.). We combine …
Optical Counterparts of the Nearest Ultraluminous X-Ray Sources
Roberts, Timothy P.; Heinke, Craig O.; Gladstone, Jeanette C. +4 more
We present a photometric survey of the optical counterparts of ultraluminous X-ray sources (ULXs) observed with the Hubble Space Telescope (HST) in nearby (lsim5 Mpc) galaxies. Of the 33 ULXs with HST and Chandra data, 9 have no visible counterpart, placing limits on their MV of ~ -4 to -9, enabling us to rule out O-type companions in 4…