Search Publications
Absolute magnitudes of OB and Be stars based on Hipparcos parallaxes - III
Wegner, W.
The absolute visual magnitudes, MV, of A-M stars are based on calculated Hipparcos trigonometric parallaxes. The sample used consists of 30986 unreddened and reddened A-M stars in luminosity classes Ia, Iab, Ib, II, III, IV and V. The colour excesses of the reddened stars were calculated using the mean colour indices, according to the S…
Radius-dependent Luminosity Evolution of Blue Galaxies in GOODS-N
Faber, S. M.; Koo, D. C.; Melbourne, J. +3 more
We examine the radius-luminosity (R-L) relation for blue galaxies in the Team Keck Redshift Survey (TKRS) of GOODS-N. We compare with a volume-limited, Sloan Digital Sky Survey sample and find that the R-L relation has evolved to lower surface brightness since z=1. Based on the detection limits of GOODS, this cannot be explained by incompleteness …
Redshifts of Emission-Line Objects in the Hubble Ultra Deep Field
Ferguson, Henry C.; Hathi, Nimish P.; Koekemoer, Anton M. +16 more
We present redshifts for 115 emission-line objects in the Hubble Ultra Deep Field identified through the Grism ACS Program for Extragalactic Science (GRAPES) project using the slitless grism spectroscopy mode of the Advanced Camera for Surveys on the Hubble Space Telescope (HST). The sample was selected by an emission-line search on all extracted …
On the origin of near-radial magnetic fields in the heliosphere: Numerical simulations
Riley, Pete; Gosling, J. T.
Deviations from the direction of the "Parker spiral" can be found in in situ measurements of the interplanetary magnetic field on essentially all scales. One intriguing subset is the intervals of near-radial magnetic field, lasting for many hours. Some such intervals are obviously associated with coronal mass ejections, while others appear to be e…
The surface brightness profile of the remote cluster NGC 2419
Bellazzini, M.
Context: It is well known that the bright and remote Galactic globular cluster NGC 2419 has a very peculiar structure. In particular its half-light radius is significantly larger than that of ordinary globular clusters of similar luminosity, being as large as that of the brightest nuclei of dwarf elliptical galaxies.
Aims: In this context it i…
Hinode observations reveal boundary layers of magnetic elements in the solar photosphere
Schmidt, W.; Lites, B. W.; Schlichenmaier, R. +3 more
Aims:We study the structure of the magnetic elements in network-cell interiors.
Methods: A quiet Sun area close to the disc centre was observed with the spectro-polarimeter of the Solar Optical Telescope on board the Hinode space mission, which yielded the best spatial resolution ever achieved in polarimetric data of the Fe I 630 nm line pair.…
Lost and Found: A New Position and Infrared Counterpart for the X-Ray Binary Scutum X-1
Erb, Dawn K.; Chakrabarty, Deepto; Moon, Dae-Sik +5 more
Using archival X-ray data, we find that the catalog location of the X-ray binary Scutum X-1 (Sct X-1) is incorrect and that the correct location is that of the X-ray source AX J183528-0737, which is 15' to the west. Our identification is made on the basis of the 112 s pulse period for this object detected in an XMM-Newton observation, as well as s…
On the relationship between coronal waves associated with a CME on 5 March 2000
Raouafi, N. -E.; Tripathi, D.
Aims:To study the relationship between coronal mass ejection (CME) associated waves.
Methods: Analysis of CME eruption observations on 5 Mar. 2000 recorded by the Large Angle Spectrometric Coronagraph (LASCO), the Ultraviolet Coronagraph Spectrometer (UVCS), and the Extreme-ultraviolet Imaging Telescope (EIT) on board the Solar and Heliospheri…
Estimation of galactic model parameters with the Sloan Digital Sky Survey and the metallicity distribution in two fields in the anti-centre direction of the Galaxy
Bilir, S.; Karaali, S.; Buser, R. +1 more
We estimated the galactic model parameters from the Sloan Digital Sky Survey (SDSS) data reduced for two fields in the anti-centre direction of the Galaxy, l= 180{o}, and symmetric relative to the galactic plane, b=+45{o} (north field) and b=-45{o} (south field). The large size of each field, 60 deg2, an…
Emission Line Variability of the Accreting Young Brown Dwarf 2MASSW J1207334-393254: From Hours to Years
Stelzer, Beate; Jayawardhana, Ray; Scholz, Alexander
We have obtained a series of high-resolution optical spectra for 2MASSW J1207334-393254 (2M 1207). Two consecutive observing nights at the ESO Very Large Telescope with the Ultraviolet and Visual Echelle Spectrograph yielded a time series with a resolution of ~12 minutes. Additional high-resolution optical spectra were obtained months apart at the…