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2 edition of Spectroscopic observations of early-type stars in the galactic halo. found in the catalog.

Spectroscopic observations of early-type stars in the galactic halo.

Francis Keenan

Spectroscopic observations of early-type stars in the galactic halo.

by Francis Keenan

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Published .
Written in English


Edition Notes

Thesis(Ph. D.)--The Queen"s University of Belfast, 1982.

The Physical Object
Pagination1 v
ID Numbers
Open LibraryOL19981827M

  Using observations of four nearby white dwarf stars in the Milky Way halo, the age of local-field halo stars is measured to be nearly around 11 billion years. An analysis of .   Wan et al. used the observations of the Southern Stellar Streams Spectroscopic Survey to measure the metallicities of 11 stars in the Phoenix stellar stream, a group of stars that orbits the.

  For the ISM in our Galaxy and the LMC, we have performed spectroscopic observations of several regions intensively in the NIR to FIR, including studies of 14 Galactic and 21 LMC SNRs. We have observed about 60 nearby galaxies, for many of which NIR to FIR images in the 10 photometric bands centered at 3, 4, 7, 11, 15, 24, 65, 90, , and   Star formation at a rate of more than 15 solar masses a year has been observed inside a massive outflow of gas from a nearby galaxy; this could also be happening inside other galactic outflows.

Figure 2 shows the abundances of S in comparison with Galactic halo and dwarf galaxy stars collected from the literature. Moreover, the measurements of Mg, Ca, Sc, Ti, and Cr agree well. Abstract. In their recent, high-quality spectroscopic observations of 59 RR Lyrae stars in Baade’s window field of the Galactic nuclear bulge, Walker and Terndrup () found that the metallicity distribution for their whole sample is sharply peaked at [Fe/H] = −


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Spectroscopic observations of early-type stars in the galactic halo by Francis Keenan Download PDF EPUB FB2

Modern star counts at high Galactic latitudes played a major role in revealing the existence of a thick disk as the third stellar component of the Milky Way Galaxy in addition to the old thin disk and halo.

A number of star count observations and models showed that the thick disk is represented well by a double exponential density law in the vertical and radial by: 4. High-resolution (R≈ Spectroscopic observations of early-type stars in the galactic halo.

book ) echelle spectroscopic observations of 13 high-latitude early-type stars are presented. These stars comprise the final part of a complete magnitude range limited sample. We present high-resolution spectroscopic observations of early-type stars drawn from a complete sample based on low-resolution spectroscopy of targets from the Palomar-Green Survey by Green, Schmidt, & Liebert.

Qualitatively, the metal-line spectra are sharp and are therefore indicative of extremely low projected rotational by: High-resolution (R~ ) echelle spectroscopic observations of 13 high-latitude early-type stars are presented. These stars comprise the final part of a complete magnitude range limited sample based on low-resolution spectroscopy of targets drawn from the Palomar-Green by:   We report Far-Ultraviolet Spectroscopic Explorer (FUSE) observations of interstellar O VI absorption in the halo of the Milky Way toward 12 early-type stars in the Large Magellanic Cloud (LMC) and 11 in the Small Magellanic Cloud (SMC).Cited by: We present photometric and spectroscopic observations of a faint star 4 arcsec away from the apparently normal, young early B-type star PG +, which was previously identified as being.

High-resolution (R ≈ 40 ) echelle spectroscopic observations of 13 high-latitude early-type stars are presented. These stars comprise the final part of a complete magnitude range limited sample based on low-resolution spectroscopy of targets drawn from the Palomar–Green survey.

Keenan's 6 research works with 36 citations and 64 reads, including: Star-forming Processes Far from the Galactic Disk: Inoperative or Indolent Where Operative. The Queen's University work is based on spectroscopic observations of 18 high-z OB stars obtained at high resolution (lambda/delta lambda = 20,) in the and nm bands with the Anglo-Australian Telescope in September and   Since most of the known runaway and HVS stars are young, early-type main-sequence stars, they cannot belong to the old halo population (see Brown for a review).

Those objects must have been formed in the Galactic disk, accelerated, and eventually injected into the halo. However, the acceleration mechanisms still remain unclear. emission line observations for a large number of stars in the Galactic halo, including all the stars in our GHRS program, and these data have been made available to us.

The high signal-to-noise cm spectra were obtained using a 20' beam and have a spectral resolution of 1. Particularly important is that they have been corrected for.

CiteSeerX - Document Details (Isaac Councill, Lee Giles, Pradeep Teregowda): We report Far Ultraviolet Spectroscopic Explorer (FUSE) observations of interstellar O VI absorption in the halo of the Milky Way towards 12 early-type stars in the Large Magellanic Cloud (LMC) and 11 in the Small Magellanic Cloud (SMC).

The mean column densities of O VI associated with the Galactic halo towards the. We have collected a large sample of recent high-resolution spectroscopic observations of unevolved stars in the Galactic halo, thick-disk and thin-disk, in bulge-like stars, globular clusters, Omega Cen, and Dwarf Spheroidal systems.

Then we compare spectroscopic observations of Cu and Zn with present stellar nucleosynthesis theory. Speeding binary star discovered approaching galactic escape velocity. be a hypervelocity, hot compact star, when it was discovered form the Sloan Digital Sky-Survey (SDSS) data in New spectroscopic observations were done with the meterre Keck II telescope at W.

Keck Observatory on Maunakea, Hawaii, and with the metre Very. Infrared photometry of four relatively faint (V = - ) early-type stars at high galactic latitude has been made in the J, H, K, L-prime and narrow-band M wavelengths. This has been combined. About early-type stars may be formed in the halo every yr by the collision of cloudlets within intermediate- and high-velocity clouds at high galactic latitude.

The origin of distant B-type stars in the galactic halo.- Galactic abundance gradients from ob-type stars in young clusters and associations.- Ionizing radiation from early-type stars.- Abundance patterns in a stars: Carbon and silicon The Galactic stellar halo consists of stars with orbits that extend to the outer regions of the galaxy.

Some of these stars will continually orbit far from the galactic center, while others are on trajectories which bring them to various distances from the galactic center. These stars. B-type stars, stars with lifetimes consistent with travel times from the Galactic center but which should not oth-erwise exist in the distant halo.

Four earlier HVS discov-eries from this survey are published elsewhere (Brown et al. a,b). Here, we present spectroscopic observa-tions of new HVS candidates.

Our paper is organized as follows. Observations were made using the m Jacobus Kapteyn Telescope (JKT) on the island of La Palma on the nights of 8th and 9th Decem-berand employed the uvby filter set along with the Tek4 High-resolution spectroscopy Programme stars for high-resolution follow-up were selected Early-type stars in the Galactic halo from the.

Spectroscopic observations of early-type stars in the galactic halo Author: Kennan, F. P. ISNI: Awarding Body: Queen's University Current Institution: Queen's University Belfast Date of Award: Availability of Full Text.Sculptoris B stars in the galactic halo --XIII/The Wolf-Rayet Stars Introduction The 3 Narrow-band photometry by interference techniques -- 4 Observations of OB stars from space vehicles -- 5 The classification problem -- V\/Interstellar Material and the OB Stars -- 1 The observation of selective extinction -- 2 The diffuse.We present imaging results from a high Galactic latitude survey designed to examine the structure of the Galactic halo.

The objective of the survey is to identify candidate halo stars which can be observed spectroscopically to obtain radial velocities and confirm halo membership.