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Accretion and Outflow in the Active Galactic Nucleus and Starburst of NGC 5135
Heckman, T. M.; Levenson, N. A.; Weaver, K. A. +2 more
Observations of the Seyfert 2 and starburst galaxy NGC 5135 with the Chandra X-Ray Observatory demonstrate that both of these phenomena contribute significantly to its X-ray emission. We spatially isolate the active galactic nucleus (AGN) and demonstrate that it is entirely obscured by column density NH>1024 cm-2
XMM-Newton Study of A3562 and Its Immediate Shapley Environs
Finoguenov, A.; Kaastra, J. S.; de Plaa, J. +2 more
Using a mosaic of six XMM-Newton observations, we study the hydrodynamic state of A3562, a cluster in the center of the Shapley supercluster. The X-ray image reveals a sharp surface brightness gradient within the core of A3562, a 200 kpc ridge extending to the southwest. A nearby group, SC 1329-313, imaged within this program also exhibits a tail …
Ni Abundance in the Core of the Perseus Cluster: An Answer to the Significance of Resonant Scattering
Gastaldello, Fabio; Molendi, Silvano
Using an XMM-Newton observation of the Perseus cluster we show that the excess in the flux of the 7-8 keV line complex previously detected by ASCA and BeppoSAX is due to an overabundance of nickel rather than to an anomalously high Fe Heβ/Fe Heα ratio. This observational fact leads to the main result that resonant scattering, which was assumed to …
XMM-Newton Observations of an Intermediate X-Ray Object in NGC 2276
Mushotzky, Richard F.; Davis, David S.
We present the results from a ~53 ks XMM-Newton observation of NGC 2276. This galaxy has an unusual optical morphology with the disk of this spiral appearing to be truncated along the western edge. This XMM-Newton observation shows that the X-ray source at the western edge is a bright intermediate X-ray object (IXO). Its spectrum is well fitted by…
On Star Effective Temperatures and H II Region Ionization Parameter Gradients in the Galaxy
Morisset, C.
Extensive photoionization model grids are computed for single-star H II regions using stellar atmosphere models from the WM-Basic code. Mid-IR emission-line intensities are predicted, and diagnostic diagrams of [Ne III/II] and [S IV/III] excitation ratios are built, taking into account the metallicities of both the star and the H II region. The di…
PSR B1951+32: A Bow Shock-confined X-Ray Nebula, a Synchrotron Knot, and an Optical Counterpart Candidate
Chatterjee, S.; Cordes, J. M.; Gallant, Y. A. +7 more
The radio pulsar PSR B1951+32 and the supernova remnant CTB 80 provide a rich laboratory for the study of neutron stars and supernova remnants. Here, we present ground-based optical and near-infrared observations of them, along with X-ray observations with Chandra and a reanalysis of archival data obtained with the Hubble Space Telescope. The X-ra…
INTEGRAL Field Spectroscopy of the Extended Ionized Gas in Arp 220
Arribas, Santiago; Colina, Luis; Clements, David
Integral field optical spectroscopy with the INTEGRAL system has been used to investigate for the first time the two-dimensional kinematic and ionization properties of the extended, warm, ionized gas in Arp 220 over an area of 75.0"×40.0" (i.e., 28×15 kpc). The structure of the ionized gas is divided into well-identified regions associated with th…
Solar Energetic Particle Acceleration in Refracting Coronal Shock Waves
Vainio, Rami; Khan, Josef I.
Gradual solar energetic particle (SEP) events are known to be correlated with coronal mass ejections (CMEs) and soft X-ray flares. The current paradigm of particle acceleration in these events attributes it to CME-driven shock waves in the solar corona and in interplanetary space. Even in small gradual SEP events related to CMEs with speeds in the…
Exploring the Upper Red Giant and Asymptotic Giant Branches: The Globular Cluster M5
Bolte, Michael; Sandquist, Eric L.
We have tabulated lists of upper red giant, horizontal-, and asymptotic giant branch (RGB, HB, and AGB) stars in the globular cluster M5 that are complete to over 10' from the core for the RGB and AGB samples, and 8' for the HB sample. The large samples give us the most precise value of R2=NAGB/NHB to date for a si…
Extended Tidal Structure in Two Lyα-emitting Starburst Galaxies
Cannon, John M.; Skillman, Evan D.; Östlin, Göran +4 more
We present new Very Large Array (VLA) C-configuration H I imaging of the Lyα-emitting starburst galaxies Tol 1924-416 and IRAS 08339+6517. The effective resolution probes neutral gas structures larger than 4.7 kpc in Tol 1924-416 and larger than 8.1 kpc in IRAS 08339+6517. Both systems are revealed to be tidally interacting: Tol 1924-416 with ESO …