Search Publications
Chandra and XMM-Newton Studies of the Supernova Remnant G292.2-0.5 Associated with the Pulsar J1119-6127
Safi-Harb, Samar; Gonzalez, Marjorie E.; Kumar, Harsha S.
We present the first detailed imaging and spatially resolved spectroscopic study of the Galactic supernova remnant (SNR) G292.2-0.5, associated with the high-magnetic field radio pulsar (PSR) J1119-6127, using Chandra and XMM-Newton. The high-resolution X-ray images reveal a partially limb-brightened morphology in the west, with diffuse emission c…
On the central stellar mass density and the inside-out growth of early-type galaxies
Longhetti, M.; Gargiulo, A.; Saracco, P.
Recent theoretical and observational studies on the assembly of early-type galaxies (ETGs) point towards an inside-out growth of their stellar mass characterized by extended low-mass-density haloes grown around compact and dense cores. Models can form ETGs at high-z as compact spheroids that then grow in size through dry minor mergers. Dry mergers…
Horizontal flow fields observed in Hinode G-band images. II. Flow fields in the final stages of sunspot decay
Liu, C.; Wang, H.; Shimizu, T. +4 more
Context. Generation and dissipation of magnetic fields is a fundamental physical process on the Sun. In comparison to flux emergence and the initial stages of sunspot formation, the demise of sunspots still lacks a comprehensive description.
Aims: The evolution of sunspots is most commonly discussed in terms of their intensity and magnetic fi…
IDCS J1426.5+3508: Cosmological Implications of a Massive, Strong Lensing Cluster at z = 1.75
Dey, Arjun; Eisenhardt, Peter R. M.; Gonzalez, Anthony H. +6 more
The galaxy cluster IDCS J1426.5+3508 at z = 1.75 is the most massive galaxy cluster yet discovered at z > 1.4 and the first cluster at this epoch for which the Sunyaev-Zel'Dovich effect has been observed. In this paper, we report on the discovery with Hubble Space Telescope imaging of a giant arc associated with this cluster. The curvature of t…
Scaling laws for magnetic fields on the quiet Sun
Stenflo, J. O.
The Sun's magnetic field is structured over a range of scales that span approximately seven orders of magnitudes, four of which lie beyond the resolving power of current telescopes. Here we have used a Hinode SOT/SP deep mode data set for the quiet-Sun disk center in combination with constraints from the Hanle effect to derive scaling laws that de…
A Candidate Active Galactic Nucleus with a Pure Soft Thermal X-Ray Spectrum
Ueda, Yoshihiro; Awaki, Hisamitsu; Terashima, Yuichi +2 more
We report the discovery of a candidate active galactic nucleus (AGN), 2XMM J123103.2+110648 at z = 0.13, with an X-ray spectrum represented purely by soft thermal emission reminiscent of Galactic black hole (BH) binaries in the disk-dominated state. This object was found in the second XMM-Newton serendipitous source catalog as a highly variable X-…
Efficient deconvolution methods for astronomical imaging: algorithms and IDL-GPU codes
Prato, M.; Cavicchioli, R.; Zanni, L. +2 more
Context. The Richardson-Lucy method is the most popular deconvolution method in astronomy because it preserves the number of counts and the non-negativity of the original object. Regularization is, in general, obtained by an early stopping of Richardson-Lucy iterations. In the case of point-wise objects such as binaries or open star clusters, iter…
Evolution in the Continuum Morphological Properties of Lyα-emitting Galaxies from z = 3.1 to z = 2.1
Gronwall, Caryl; Gawiser, Eric; Ciardullo, Robin +4 more
We present a rest-frame ultraviolet morphological analysis of 108 z ~= 2.1 Lyα emitters (LAEs) in the Extended Chandra Deep Field South and compare it to a similar sample of 171 LAEs at z ~= 3.1. Using Hubble Space Telescope images from the Galaxy Evolution from Morphology and SEDs survey, Great Observatories Origins Deep Survey, and Hubble Ultrad…
Rest-frame UV-Optically Selected Galaxies at 2.3 <~ z <~ 3.5: Searching for Dusty Star-forming and Passively Evolving Galaxies
Dickinson, Mark; Ferguson, Henry C.; Fontana, Adriano +17 more
A new set of color selection criteria (VJL) analogous with the BzK method is designed to select both star-forming galaxies (SFGs) and passively evolving galaxies (PEGs) at 2.3 <~ z <~ 3.5 by using rest-frame UV-optical (V - J versus J - L) colors. The criteria are thoroughly tested with theoretical stellar population synthesis models and rea…
HS 1700+6416: the first high-redshift unlensed narrow absorption line-QSO showing variable high-velocity outflows
Cappi, M.; Vignali, C.; Dadina, M. +4 more
We present a detailed analysis of the X-ray emission of HS 1700+6416, a high-redshift (z = 2.7348) luminous quasar classified as a narrow absorption line (NAL) quasar on the basis of its SDSS spectrum. The source has been observed nine times by Chandra and once by XMM-Newton from 2000 to 2007. Long-term variability is clearly detected between the …