Search Publications
Core Radio and Optical Emission in the Nuclei of nearby FR I Radio Galaxies
Baum, Stefi A.; O'Dea, Christopher P.; de Zeeuw, P. Tim +1 more
In this paper we analyze the relation between radio, optical continuum and Hα+[N II] emission from the cores of a sample of 21 nearby Fanaroff and Riley type I galaxies as observed with the VLBA and HST. The emission arises inside the inner tens of parsecs of the galaxies. Core radio emission is observed in 19/20 galaxies, optical core continuum e…
A Classical Nova, V2487 Oph 1998, Seen in X-rays Before and After Its Explosion
Hernanz, Margarita; Sala, Glòria
Classical nova explosions are very energetic and frequent phenomena caused by explosive hydrogen burning on top of an accreting white dwarf. Observations of the recent nova V2487 Oph 1998 by the X-ray Multi-Mirror satellite (XMM-Newton) provide evidence that accretion (probably on a magnetic white dwarf) was reestablished as early as 2.7 years aft…
An Hα survey of the rich cluster A 1689
Smail, Ian; Glazebrook, Karl; Balogh, Michael L. +2 more
We present results of an Hα survey in the rich cluster A 1689 at z= 0.18, using the LDSS++ spectrograph on the Anglo-Australian Telescope (AAT). We obtained spectra covering redshifted Hα at z= 0.16-0.22, for 522 galaxies brighter than I= 22.5, covering a field of 8.7 × 8.7 arcmin2 (~1.1 × 1.1 h-1 Mpc at z= 0.18). We securely…
The ultraviolet line spectrum of the soft X-ray transient XTE J1118+480: a CNO-processed core exposed
King, A. R.; Haswell, C. A.; Hynes, R. I. +1 more
We compare ultraviolet (UV) spectra of the recent soft X-ray transients XTE J1118+480 and XTE J1859+226. The emission line strengths in XTE J1118+480 strongly suggest that the accreting material has been CNO processed. We show that this system must have come into contact with a secondary star of about 1.5Msolar, and an orbital period ~1…
Does the Sun Have a Full-Time COmosphere?
Ayres, Thomas R.
Off-limb emissions of solar 4.7 µm rovibrational bands of carbon monoxide, recorded under excellent observing conditions with the Infrared Imaging Spectrograph at the McMath-Pierce telescope, are compared with theoretical translimb CO simulations based on time slices from the Carlsson & Stein dynamical model of chromospheric ``K grains.'…
The Far-Infrared Energy Distributions of Seyfert and Starburst Galaxies in the Local Universe: Infrared Space Observatory Photometry of the 12 Micron Active Galaxy Sample
Spinoglio, Luigi; Malkan, Matthew A.; Andreani, Paola
New far-infrared photometry with ISOPHOT aboard the Infrared Space Observatory (ISO) is presented for 58 galaxies with homogeneous published data for another 32 galaxies, all belonging to the 12 µm galaxy sample-in total, 29 Seyfert 1 galaxies, 35 Seyfert 2 galaxies, and 12 starburst galaxies, or about half of the 12 µm active galaxy s…
Reddening, Emission-Line, and Intrinsic Absorption Properties in the Narrow-Line Seyfert 1 Galaxy Arakelian 564
Brandt, W. N.; Clavel, J.; Kriss, G. A. +14 more
We use Hubble Space Telescope UV and optical spectra of the narrow-line Seyfert 1 (NLS1) galaxy Ark 564 to investigate its internal reddening and properties of its emission-line and intrinsic UV absorption gas. We find that the extinction curve of Ark 564, derived from a comparison of its UV/optical continuum to that of an unreddened NLS1, lacks a…
XMM-Newton observations of ultraluminous X-ray sources in nearby galaxies
Cappi, M.; Piconcelli, E.; Foschini, L. +9 more
An XMM-Newton study of ultraluminous X-ray sources (ULX) has been performed in a sample of 10 nearby Seyfert galaxies. Eighteen ULX have been found with positional uncertainty of about 4''. The large collecting area of XMM-Newton makes the statistics sufficient to perform spectral fitting with simple models in 8 cases. The main results of the pres…
Fe II/Mg II Emission-Line Ratios of QSOs within 0 < z < 5.3
Doi, Mamoru; Yoshii, Yuzuru; Motohara, Kentaro +3 more
Near-infrared spectra of 13 QSOs located between 4.4<z<5.3 were obtained by the OH-airglow suppression spectrograph mounted on the Subaru telescope. The Fe II/Mg II emission-line ratios of the QSOs at various redshifts were examined by applying the same fitting algorithm to the present data together with published or archived spectra. We fou…
Carbon-rich giants in the HR diagram and their luminosity function
Bergeat, J.; Knapik, A.; Rutily, B.
The luminosity function (LF) of nearly 300 Galactic carbon giants is derived. Adding BaII giants and various related objects, about 370 objects are located in the RGB and AGB portions of the theoretical HR diagram. As intermediate steps, (1) bolometric corrections are calibrated against selected intrinsic color indices; (2) the diagram of photomet…