Search Publications
Completion of a Survey and Detailed Study of Double-peaked Emission Lines in Radio-loud Active Galactic Nuclei
Eracleous, Michael; Halpern, Jules P.
We report the completion of a survey of radio-loud active galactic nuclei (AGNs) begun in an earlier paper with the main goal of finding and studying broad, double-peaked Balmer lines. We present Hα spectra of 13 more broad-lined objects, including three with double-peaked Hα profiles. The final sample includes 106 radio-loud AGNs. In our final ce…
Vertical distribution of Galactic disk stars. I. Kinematics and metallicity
Soubiran, C.; Siebert, A.; Bienaymé, O.
Nearly 400 Tycho-2 stars have been observed in a 720 square degree field in the direction of the North Galactic Pole with the high resolution echelle spectrograph ELODIE. Absolute magnitudes, effective temperatures, gravities and metallicities have been estimated, as well as distances and 3D velocities. Most of these stars are clump giants and spa…
A New Empirical Model for the Structural Analysis of Early-Type Galaxies, and A Critical Review of the Nuker Model
Graham, Alister W.; Trujillo, I.; Asensio Ramos, A. +1 more
The Nuker law was designed to match the inner few (~3-10) arcseconds of predominantly nearby (<~30 Mpc) early-type galaxy light profiles; it was never intended to describe an entire profile. The Sérsic model, on the other hand, was developed to fit the entire profile; however, because of the presence of partially depleted galaxy cores, the Sérs…
Multiplicity among solar-type stars. III. Statistical properties of the F7-K binaries with periods up to 10 years
Arenou, F.; Udry, S.; Mayor, M. +1 more
Two CORAVEL radial velocity surveys - one among stars in the solar neighbourhood, the other in the Pleiades and in Praesepe - are merged to derive the statistical properties of main-sequence binaries with spectral types F7 to K and with periods up to 10 years. A sample of 89 spectroscopic orbits was finally obtained. Among them, 52 relate to a fre…
Discovery of X-Ray Quasi-periodic Oscillations from an Ultraluminous X-Ray Source in M82: Evidence against Beaming
Mushotzky, Richard F.; Strohmayer, Tod E.
We report the discovery with the European Photon Imaging Camera CCDs on board XMM-Newton of a 54 mHz quasi-periodic oscillation (QPO) in the greater than 2 keV X-ray flux from an ultraluminous X-ray source (ULX) in the starburst galaxy M82. This is the first detection of a QPO in the X-ray flux from an extragalactic ULX and confirms that the sourc…
The three-dimensional solar wind around solar maximum
McComas, D. J.; Goldstein, B. E.; Schwadron, N. A. +3 more
Ulysses is now completing its second solar polar orbit, dropping back down in latitude as the Sun passes through its post-maximum phase of the solar cycle. A mid-sized circumpolar coronal hole that formed around solar maximum in the northern hemisphere has persisted and produced a highly inclined CIR, which was observed from ~70°N down to ~30°N. W…
Investigation of 131 Herbig Ae/Be Candidate Stars
Alencar, S. H. P.; Corradi, W. J. B.; Guimarães, M. M. +5 more
We present a new catalog of 108 Herbig Ae/Be candidate stars identified in the Pico dos Dias Survey, together with 19 previously known candidates and four objects selected from the IRAS Faint Source Catalog. These 131 stars were observed with low- and/or medium-resolution spectroscopy, and we complement these data with high-resolution spectra of 3…
On the Interaction between Convection and Magnetic Fields
Cattaneo, Fausto; Emonet, Thierry; Weiss, Nigel
Turbulent convection in the solar photosphere can act as a small-scale dynamo, maintaining a disordered magnetic field that is locally intense. On the other hand, convection is inhibited in the presence of a strong, externally imposed magnetic field, as for instance, in a sunspot. Large-scale, three-dimensional, numerical experiments on highly non…
Determination of the gas-to-dust ratio in nearby dense clouds using X-ray absorption measurements
Grosso, N.; Montmerle, T.; Feigelson, E. D. +3 more
We present a comparison of the gas and dust properties of the dense interstellar matter in six nearby star-forming regions (d<500 pc): rho Oph, Cha I, R CrA, IC 348, NGC 1333, and Orion. We measure from Chandra and XMM-Newton observations the X-ray absorption toward pre-main sequence stars (PMS) without accretion disks (i.e., Class III sources)…
Current sheet structure near magnetic X-line observed by Cluster
Balogh, A.; Zhang, T. L.; Klecker, B. +9 more
During the interval 0947-0951 UT on 1 October 2001, when Cluster was located at X GSM = -16.4 R E near Z GSM = 0 in the pre-midnight magnetotail, the Cluster barycenter crosses the neutral sheet four times. High speed proton flow, with reversal from tailward to Earthward, was detected during the crossings. Us…