ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Other Sources  (21)
Collection
Source
Keywords
Years
  • 1
    facet.materialart.
    Unknown
    The WARPS survey for faint clusters of galaxies (1996)
    In:  CASI
    Details
    Publication Date: 2004-12-03
    Description: The wide angle Rosat pointed survey (WARPS) of clusters is based on the Rosat position sensitive proportional counter (PSPC) archive of pointed observations. It includes extended X-ray sources and point-like X-ray sources with non-stellar optical counterparts. It was designed to minimize the selection effects while covering a large area of the sky. The purposes of the survey were to measure the low luminosity, high redshift, X-ray luminosity function of clusters and groups and to investigate cluster morphologies and unusual systems.
    Keywords: Astronomy
    Type: ; 591-592
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 2
    facet.materialart.
    Unknown
    The CI pressure shift and gravitational redshift of the cool DBQA5 white dwarf LDS678A (1990)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: A high resolution ultraviolet spectrum of the helium rich degenerate LDS 678A, obtained with the International Ultraviolet Explorer (IUE) satellite is presented. LDS 678A is the coolest metallic line generate (DQ or DZ) yet observed with the IUE scale. These observations provide a detailed line profile of the strong C I 2479 absorption line with equivalent width (W sub 2479 = 2.35 plus or minus 0.06 angstroms) from which theoretical line profile fits yield a C abundance (log C/He = 6.4). The presence of carbon in a helium rich atmosphere lends credence to the notion that LDS 678A is a transitional case between the DB white dwarfs with nearly pure helium atmospheres and the helium rich DQ white dwarfs which exhibit carbon bands. Corrected for an inferred pressure shift for the C I line, a gravitational redshift is deduced from which a most probable mass of 0.55 solar mass is derived.
    Keywords: ASTROPHYSICS
    Type: ESA, Evolution in Astrophysics: IUE Astronomy in the Era of New Space Missions; p 467-470
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 3
    facet.materialart.
    Unknown
    Ultraviolet carbon lines in the spectrum of the white dwarf BPM 11668 (1983)
    In:  Other Sources
    Details
    Publication Date: 2019-06-28
    Description: The southern hemisphere DC white dwarf BPM 11668 has been found to show strong ultraviolet lines of neutral carbon using observations from the IUE satellite. This star seems typical of the growing number of DC white dwarfs found to be of this type and appears to have a carbon abundance near C:He = 0.0001, with an effective temperature of 8500 K.
    Keywords: ASTROPHYSICS
    Type: Astronomy and Astrophysics (ISSN 0004-6361); 128; 1; 258
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 4
    facet.materialart.
    Unknown
    The cool DC white dwarf Stein 2051B (1983)
    In:  Other Sources
    Details
    Publication Date: 2019-06-28
    Description: Visual scans from the Kitt-Peak 2.1-m telescope and UV spectra from the IUE satellite are combined in a spectroscopic study of the bright DC white dwarf, Stein 2051B. With a cooling age near 2 billion years, and a resulting atmospheric mass of hydrogen of the order of 6 x 10 to the 17th g, the accretion rate over the star's lifetime is less than 2 x 10 to the -25th solar masses/year. This is far below the predictions of standard accretion theories, and requires unreasonably strong suppression of hydrogen accretion in this star if the accretion-diffusion theory is to account for the carbon abundance found. It is suggested that the carbon may have been brought to the surface by convective mixing.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal, Part 1 (ISSN 0004-637X); 275; 240-246
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 5
    facet.materialart.
    Unknown
    Observations of ultraviolet carbon lines in the spectra of three DC white dwarfs (1983)
    In:  Other Sources
    Details
    Publication Date: 2019-06-28
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal, Part 1 (ISSN 0004-637X); 268; May 1
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 6
    facet.materialart.
    Unknown
    Observations of strong ultraviolet absorptions in the spectrum of the DC white dwarf LDS 678 B (1981)
    In:  Other Sources
    Details
    Publication Date: 2019-06-28
    Description: Evidence from spectroscopic observations that LDS 678 B has strong ultraviolet lines of neutral carbon in its spectrum is presented. The spectra are found to contain strong lines of C I in the ultraviolet and weak He I lines in the visible. The appearance of the star's spectrum and published photometry are consistent with its having an effective temperature near 10,600 K with a helium-dominated atmosphere and a carbon abundance lower than C:He = 0.001. The star's spectra are compared with those of the white dwarfs L879-14 and L145-141, which are cooler than LDS 678B, have C2 bands in the visible and also show strong evidence of strong ultraviolet C I lines. It is concluded that LDS 678 B has a temperature intermediate between the DB and C2 band white dwarfs and that the ultraviolet C I lines can be a useful means for finding carbon in the atmosphere of the cooler white dwarfs.
    Keywords: ASTRONOMY
    Type: Astrophysical Journal; vol. 245
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 7
    facet.materialart.
    Unknown
    Variations in the mass flow from Zeta Puppis (1980)
    In:  Other Sources
    Details
    Publication Date: 2019-06-27
    Description: Detailed simultaneous visible and ultraviolet spectroscopy of Zeta Puppis was carried out in order to study the time scale of variations in its stellar wind and to assess the relationship between fluctuations in lines of ions formed at different heights. The observed variations were most striking in the He II 4686 A profile, but were also seen in H alpha and in the resonance doublets of Si IV and O VI. Fluctuations in the visible features occurred in times of about one hour, while the ultraviolet profiles showed changes which took several hours to develop. No evidence of periodicity was seen, but the time coverage is not sufficiently complete to preclude it. Specific changes, particularly in H alpha and 4686 A, may have been caused by the passage of density enhancements from the stellar surface outward through the wind. The profile variations, when compared with recent model calculations, imply changes in the mass-loss rate by no more than a factor of two in times of a few hours.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; vol. 238
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 8
    facet.materialart.
    Unknown
    Observations of the strong ultraviolet absorptions in the spectrum of the DC white dwarf G218-8 (1981)
    In:  Other Sources
    Details
    Publication Date: 2019-06-28
    Description: The spectrum of the 14th magnitude DC white dwarf G218-8 (EG 245) is described. In the visible spectral region the star has been observed with the IIDS scanner attached to the Kitt Peak National Observatory 2.1 m telescope, where it shows a featureless spectrum. However, the ultraviolet observations using the IUE satellite show that strong absorption lines attributable to neutral carbon are present. G218-8 has an effective temperature near 11,500 K and a helium dominated atmosphere with a carbon-to-helium abundance ratio less than or approximately equal to 0.005.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal; vol. 248
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 9
    facet.materialart.
    Unknown
    An analysis of the bright white dwarf CD - 38 deg 10980 (1985)
    In:  Other Sources
    Details
    Publication Date: 2019-06-28
    Description: The bright DA white dwarf CD - 38 deg 10980 is comprehensively analyzed using all available data. Detailed comparisons of the overall energy distribution and Lyman-alpha and Balmer profiles are made with theoretical predictions based on a homogeneous grid of model atmospheres. These comparisons yield a consistent, well-defined effective temperature and surface gravity for this star of 24,700 + or - 250 K and log g = 7.95 + or - 0.15, respectively. A new gravitational redshift of 28.4 + or - 4.8 km/s is derived from an IUE high-dispersion spectrum. Conclusions regarding the mass and radius of CD - 38 deg 10980 are also presented.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal, Part 1 (ISSN 0004-637X); 293; 294-302
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 10
    facet.materialart.
    Unknown
    Identification of the 1400 and 1600 A features observed in the ultraviolet spectra of DA white dwarfs (1985)
    In:  Other Sources
    Details
    Publication Date: 2019-06-28
    Description: The 600 A absorption feature in the spectra of cool DA white dwarf stars has been identified as a resonance broadening of Ly-alpha due to the hydrogen quasi molecule. Likewise, the 1400 A absorption feature in the spectra of cool and moderately warm DA white dwarf stars appears to be due to a Ly-alpha satellite line arising from the hydrogen ion quasi molecule. The strength of both features is gravity sensitive and therefore promises to be an excellent indicator of surface gravity.
    Keywords: ASTROPHYSICS
    Type: Astrophysical Journal, Part 2 - Letters to the Editor (ISSN 0004-637X); 289; L31-L33
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...