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The ISO-SWS spectrum of NML Cyg.
Waters, L. B. F. M.; Beintema, D. A.; Izumiura, H. +9 more
The high resolution spectrum of NML Cyg observed with the ISO-SWS in its slow-speed grating mode (2.4-45µm) shows a wealth of features never seen before in previous observations. These include ro-vibrational lines of H_2_O at 2.7 and 6.2µm, of OH between 3 and 3.5µm and a deep absorption band of CO_2_ at 4.26µm. We also rep…
Hubble Space Telescope Observations of Globular Clusters in M31.I.Color- Magnitude Diagrams, Horizontal Branch Metallicity Dependence, and the Distance to M31
Holtzman, J. A.; Faber, S. M.; Grillmair, C. J. +5 more
This paper presents Hubble Space Telescope observations of four globular clusters in M31 with [Fe/H] ranging from -0.6 to -2.0. The Wide-Field and Planetary Camera-2 (WFPC-2) imaged these clusters through the F555W (V) and F814W (I) filters with total exposure times of 2000 s in each color. The ground-based spectroscopic metallicities are generall…
The Nuclear Starburst Driven by a Supermassive Black Hole Binary
Wada, Keiichi; Taniguchi, Yoshiaki
We propose a new formation mechanism of the nuclear starburst and hot- spot nuclei: a supermassive black hole binary formed by a merger with a nucleated satellite galaxy triggers intense star formation in the central regions of spiral galaxies in which the nuclear gas disk has been formed already by the dynamical effect of the merger itself. As th…
Galaxy Clustering around Nearby Luminous Quasars
Schneider, Donald P.; Bahcall, John N.; Kirhakos, Sofia +1 more
We examine the clustering of galaxies around a sample of 20 luminous low redshift ( z <~ 0.30) quasars observed with the Wide Field Camera-2 on the Hubble Space Telescope (HST). The HST resolution makes possible galaxy identification brighter than V = 24.5 and as close as 1" or 2" to the quasar. We find a significant enhancement of galaxies wit…
Starcounts Redivivus II: Deep Starcounts With Keck and HST and the Luminosity Function of the Galactic Halo
Smail, Ian; Thompson, Ian; Yan, Lin +2 more
We have combined deep starcount data with Galaxy model predictions to investigate how effectively such measurements probe the faint end of the halo luminosity function. We have tested a number of star/galaxy classification techniques using images taken in 0.5 arcsec seeing with LRIS on the Keck telescope, and we find that different combinations of…
The Intermediate Stellar Mass Population in NGC 604 Determined from Hubble Space Telescope Images
Lynds, Roger; O'Neil, Earl J., Jr.; Baum, William A. +1 more
We present photometry of stars in the giant H II region NGC 604 in M33. The photometry is measured from Hubble Space Telescope images through the F336W, F555W, and F814W broadband filters. Color-magnitude diagrams of the stars in NGC 604 show a main sequence detected down to an MF555W,0 of -1 (nearly 6 Msun). In addition, there are…
The Inscrutable Hot Component in the Symbiotic Binary Z Andromedae
Mikolajewska, Joanna; Kenyon, Scott. J.
We analyze optical and ultraviolet spectroscopic observations of the symbiotic binary star Z Andromedae. This system consists of an M3 -M4 giant and a hot component surrounded by an ionized nebula. The orbital mass function is consistent with Mg∼Msun and Msunh∼0.5-1 Msun as in other…
Cepheid Calibration of the Peak Brightness of Type IA Supernovae. VI. SN 1960F in NGC 4496A
Panagia, N.; Saha, A.; Labhardt, Lukas +3 more
Cepheid variables have been found in the SBcII galaxy NGC 4496A, parent to the Type Ia supernova 1960F. Of the 130 variables discovered with the Hubble Space Telescope (HST) over a 70 day observing internal from 1994 June to August, comprising 17 epochs in the F555W band and four epochs in the F814W band, 95 are bona fide Cepheids. The periods ran…
Globular Cluster Photometry With the Hubble Space Telescope. V. WFPC Study of M15's Central density Cusp
Schneider, Donald P.; Yanny, Brian; Bahcall, John N. +1 more
We describe images of the center of the dense globular cluster M15 (NGC 7078) obtained with the Hubble Space Telescope Wide Field and Planetary Camera 2 (WFPC2). Data taken in the F336W, F439W, and F555W filters (approximately U, B, and V) are used to study the surface density distribution of the ∼3×104 stars detected in a 5 arcmin…
The Sombrero galaxy. II. Colours, kinematics and line strengths of the central region.
Emsellem, E.; Bacon, R.; Monnet, G. +1 more
We present photometric (pre-COSTAR HST and ground-based) and new two-dimensional TIGER spectrographic data of the central region of the Sombrero galaxy (NGC 4594, M 104). This gives B-V and V-R_C_ images, as well as 2D line strengths and kinematical maps (LOSVDs). Analysis of these data lets us draw a clearer picture of the morphology of the Sombr…