Astrophysics Pristine CNO abundances from Magellanic Cloud B stars
... whether the N abundances already found are representative of LMC B stars in general. In contrast to the paucity of data on dwarfs, many MC supergiants – from spectral type O to K – have been studied in detail (e.g. Haser et al 1998: O-type, Paper I: B-type, Venn 1999b: A-type, Andrievsky et al. 2001 ...
... whether the N abundances already found are representative of LMC B stars in general. In contrast to the paucity of data on dwarfs, many MC supergiants – from spectral type O to K – have been studied in detail (e.g. Haser et al 1998: O-type, Paper I: B-type, Venn 1999b: A-type, Andrievsky et al. 2001 ...
Explosive sources of the highest energy radiation
... During this period the average >100 MeV flux nova explosion reported by Chinese astronoof the system was 0.9 × 10 –10 erg cm –2 s –1. What mers in AD 1054. At the heart of the nebula is was completely unexpected was that 30 days a pulsar that loses rotational energy through a after periastron passag ...
... During this period the average >100 MeV flux nova explosion reported by Chinese astronoof the system was 0.9 × 10 –10 erg cm –2 s –1. What mers in AD 1054. At the heart of the nebula is was completely unexpected was that 30 days a pulsar that loses rotational energy through a after periastron passag ...
Summary of Talks at Growing Black Holes 2004 in Garching
... Statistics : Overall fraction of AGN in the sample >50% for nearby L* galaxies at low redshift. Fraction declines toward higher z (because of increasing stellar contamination in the 3 arcsec fiber?) The AGNs are similar to the red galaxies in terms of structural properties. In terms of stellar p ...
... Statistics : Overall fraction of AGN in the sample >50% for nearby L* galaxies at low redshift. Fraction declines toward higher z (because of increasing stellar contamination in the 3 arcsec fiber?) The AGNs are similar to the red galaxies in terms of structural properties. In terms of stellar p ...
1 Introduction - High Point University
... Table 6: Fill in the empty fields above. 3. Check show luminosity classes and show isoradius lines (if they are not already checked). The green region (Dwarfs (V)) is known as the main sequence and contains all stars that are fusing hydrogen into helium as their primary energy source. Over 90% of al ...
... Table 6: Fill in the empty fields above. 3. Check show luminosity classes and show isoradius lines (if they are not already checked). The green region (Dwarfs (V)) is known as the main sequence and contains all stars that are fusing hydrogen into helium as their primary energy source. Over 90% of al ...
Evolution of galaxy morphology - Lecture 1 - NCRA-TIFR
... Today, many other criteria such as color indices, spectroscopic parameters (based on emission or absorption lines), the broad-band spectral energy distribution (galaxies with/without radio- and/or X-ray emission) are also used to group similar galaxies together. ...
... Today, many other criteria such as color indices, spectroscopic parameters (based on emission or absorption lines), the broad-band spectral energy distribution (galaxies with/without radio- and/or X-ray emission) are also used to group similar galaxies together. ...
Introduction to Observational Cosmology
... (separate flux limit in each observational band). – For extended objects surveys are surface brightness limited (i.e. limited by the contrast to the background) ...
... (separate flux limit in each observational band). – For extended objects surveys are surface brightness limited (i.e. limited by the contrast to the background) ...
THE ABSOLUTE MAGNITUDE OF RR LYRAE - Cosmos
... of the current literature by Chaboyer et al. (1996a): MV = 0:98 + 0:20[Fe=H]. To see the dependence of the results on the stellar density distribution n(r), we calculate the case for n(r) / r2 (see Reid 1997) and obtain the same result, by which the insensitivity of the results to the density distri ...
... of the current literature by Chaboyer et al. (1996a): MV = 0:98 + 0:20[Fe=H]. To see the dependence of the results on the stellar density distribution n(r), we calculate the case for n(r) / r2 (see Reid 1997) and obtain the same result, by which the insensitivity of the results to the density distri ...
The first photometric analysis of the overcontact binary MQ UMa with
... an A-subtype contact binary with a high fill-out (f=82 %) and a low mass ratio (q = 0.195), which indicates that it is in the late evolutionary stage of latetype tidal-locked binary stars. The mass of the primary and secondary stars are estimated and the evolutionary status of the two components are ...
... an A-subtype contact binary with a high fill-out (f=82 %) and a low mass ratio (q = 0.195), which indicates that it is in the late evolutionary stage of latetype tidal-locked binary stars. The mass of the primary and secondary stars are estimated and the evolutionary status of the two components are ...
Barger - Chandra X-Ray Observatory (CXC)
... redshift estimates and use them to construct luminosity functions ...
... redshift estimates and use them to construct luminosity functions ...
Star 1 A star is a massive, luminous ball of plasma held together by
... For at least a portion of its life, a star shines due to thermonuclear fusion of hydrogen in its core releasing energy that traverses the star's interior and then radiates into outer space. Almost all naturally occurring elements heavier than helium were created by stars, either via stellar nucleosy ...
... For at least a portion of its life, a star shines due to thermonuclear fusion of hydrogen in its core releasing energy that traverses the star's interior and then radiates into outer space. Almost all naturally occurring elements heavier than helium were created by stars, either via stellar nucleosy ...
AAVSO: Epsilon Aurigae
... Most recent interpretations of the observations seem to confirm the model set forth in 1991. It is now likely that there is an early-type binary system with components having spectral class B5 or earlier at the center of the disk, based upon the ultraviolet spectrum obtained with FUSE (Bennett et al ...
... Most recent interpretations of the observations seem to confirm the model set forth in 1991. It is now likely that there is an early-type binary system with components having spectral class B5 or earlier at the center of the disk, based upon the ultraviolet spectrum obtained with FUSE (Bennett et al ...
Stages of star formation (the classical view)
... when there is a pumping mechanism: transitions to and from other levels, which can be able to overpopulate the upper level 2. Pumping can be represented by a third level, with a rate P12, of excitation transitions from level 1 to 2, through level 3, and a rate P21, of desexcitation transitions from ...
... when there is a pumping mechanism: transitions to and from other levels, which can be able to overpopulate the upper level 2. Pumping can be represented by a third level, with a rate P12, of excitation transitions from level 1 to 2, through level 3, and a rate P21, of desexcitation transitions from ...
The Jansky Very Large Array – New Capabilities, New Science
... observations as well as VLA. • The rise of ALMA will strengthen this complementarity, with stellar scientific results. • New example – Wagg and Carilli combine VLA and ALMA for early forming galaxies: – Massive galaxies at z~2 must have formed at earlier epochs. – Formation phase seems to have been ...
... observations as well as VLA. • The rise of ALMA will strengthen this complementarity, with stellar scientific results. • New example – Wagg and Carilli combine VLA and ALMA for early forming galaxies: – Massive galaxies at z~2 must have formed at earlier epochs. – Formation phase seems to have been ...
Process of Science: PreMainSequence Stellar Life Tracks on the HR
... If you watch the position of the red dot on the HR diagram as the interactive figure plays, you will see that the dot is highest — meaning the object is most luminous— when it is a protostar and therefore does not yet have internal fusion. This fact can be a little surprising, but do not forget tha ...
... If you watch the position of the red dot on the HR diagram as the interactive figure plays, you will see that the dot is highest — meaning the object is most luminous— when it is a protostar and therefore does not yet have internal fusion. This fact can be a little surprising, but do not forget tha ...
Is there a Supermassive Black Hole at the Center of the Milky Way?
... of about 6.4 keV. This line probably arises form material in an accretion disk inside of 10RSch of a SMBH where Doppler and gravitational redshifts are large. (Reprinted by permission of Macmillan Publishers Ltd: Nature, 375, 1995, 659) ...
... of about 6.4 keV. This line probably arises form material in an accretion disk inside of 10RSch of a SMBH where Doppler and gravitational redshifts are large. (Reprinted by permission of Macmillan Publishers Ltd: Nature, 375, 1995, 659) ...
An introduction to photometry and photometric measurements Henry
... bright -- so a network of secondary standards of fainter sources have been established. • The Landolt system, based on A0 stars has become the standard magnitude system for many applications. • Landolt measured stellar magnitudes using photoelectric photometers with a 14” (!) aperture; while making ...
... bright -- so a network of secondary standards of fainter sources have been established. • The Landolt system, based on A0 stars has become the standard magnitude system for many applications. • Landolt measured stellar magnitudes using photoelectric photometers with a 14” (!) aperture; while making ...
SherwoodWA_1973redux - Edinburgh Research Archive
... 1970; Gottesman and Davis, 1970) found that the HII regions and blue supergiants (in associations) lie within the ...
... 1970; Gottesman and Davis, 1970) found that the HII regions and blue supergiants (in associations) lie within the ...
– 1 – 1. Galaxy Observations 1.1.
... The major concern in studies based on SDSS spectra is the fixed fiber size of 3 arcsec, which means aperture corrections are important as the spatial sampling varies from “nuclear spectra” to “partial or full disk spectra” depending on the redshift. Given radial gradients in metallicity (and in many ...
... The major concern in studies based on SDSS spectra is the fixed fiber size of 3 arcsec, which means aperture corrections are important as the spatial sampling varies from “nuclear spectra” to “partial or full disk spectra” depending on the redshift. Given radial gradients in metallicity (and in many ...
Exploring Neutral Hydrogen and Galaxy Evolution with the SKA
... Analysis of thousands of galaxies in the Sloan Digital Sky Survey (SDSS) has shown that they follow a bimodal distribution in colour as a function of stellar mass (Baldry et al. (2004)); most galaxies are either located in the so-called blue cloud or on the red sequence, indicating that star formati ...
... Analysis of thousands of galaxies in the Sloan Digital Sky Survey (SDSS) has shown that they follow a bimodal distribution in colour as a function of stellar mass (Baldry et al. (2004)); most galaxies are either located in the so-called blue cloud or on the red sequence, indicating that star formati ...
here - Ira-Inaf
... shows a strong concentration at the Galactic Center and a sharp decrease to about 2 kpc, followed by a marked increase peaking at the so-called “Molecular Ring” at about 4–6 kpc. At larger RG there is a gradual drop-off in concentration to about 18–20 kpc (Scoville and Sanders, 1987; Wouterloot et a ...
... shows a strong concentration at the Galactic Center and a sharp decrease to about 2 kpc, followed by a marked increase peaking at the so-called “Molecular Ring” at about 4–6 kpc. At larger RG there is a gradual drop-off in concentration to about 18–20 kpc (Scoville and Sanders, 1987; Wouterloot et a ...
A GMOS dissection of the line-of
... This displacement is comparable to that seen with other galaxies associated with MgII absorbers. Redshift slightly different though. Closest possible galaxy is ~20kpc, but is fainter (hence smaller). ...
... This displacement is comparable to that seen with other galaxies associated with MgII absorbers. Redshift slightly different though. Closest possible galaxy is ~20kpc, but is fainter (hence smaller). ...
Constellation Guide Book
... People like to look at the stars at night. They want to see the constellations. Many people use constellation guides to help them find the constellations. These guides also include information about each constellation. Your assignment is to make a guide to fall constellations. You have an informatio ...
... People like to look at the stars at night. They want to see the constellations. Many people use constellation guides to help them find the constellations. These guides also include information about each constellation. Your assignment is to make a guide to fall constellations. You have an informatio ...
ROTATION CURVES OF HIGH-LUMINOSITY SPIRAL GALAXIES
... Current values of 0ort s constants are A = 15.6±2.8, B = -11.4±2.8 km/s per kpc (Fricke and Tsioumis 1975), although 0-B2 stars produce values as discrepant as A = +26, B = -37 (Asteriadis, 1977). At the la level, A = -B is not excluded, i.e., the rotation curve could be flat in the solar vicinity. ...
... Current values of 0ort s constants are A = 15.6±2.8, B = -11.4±2.8 km/s per kpc (Fricke and Tsioumis 1975), although 0-B2 stars produce values as discrepant as A = +26, B = -37 (Asteriadis, 1977). At the la level, A = -B is not excluded, i.e., the rotation curve could be flat in the solar vicinity. ...
Building galaxies Hunt, Leslie Kipp
... Perhaps the most beautiful sight in the night sky visible to the naked eye is our own galaxy, the Via Lactea or Milky Way. That it was composed of individual stars was recognized only in the early seventeenth century by Galileo with his telescope; this was the beginning of the study of galaxies as s ...
... Perhaps the most beautiful sight in the night sky visible to the naked eye is our own galaxy, the Via Lactea or Milky Way. That it was composed of individual stars was recognized only in the early seventeenth century by Galileo with his telescope; this was the beginning of the study of galaxies as s ...
The Clouds
... stars has been forming for about 7 Myr just on the right edge of the cloud, region 1b, sweeping up and disrupting the cloud in the process. Some stars are now visible while others remain embedded. The latest generation only began about 3 Myr in location 1c. All these objects are still embedded and s ...
... stars has been forming for about 7 Myr just on the right edge of the cloud, region 1b, sweeping up and disrupting the cloud in the process. Some stars are now visible while others remain embedded. The latest generation only began about 3 Myr in location 1c. All these objects are still embedded and s ...
Serpens
Serpens (""the Serpent"", Greek Ὄφις) is a constellation of the northern hemisphere. One of the 48 constellations listed by the 2nd-century astronomer Ptolemy, it remains one of the 88 modern constellations defined by the International Astronomical Union. It is unique among the modern constellations in being split into two non-contiguous parts, Serpens Caput (Serpent's Head) to the west and Serpens Cauda (Serpent's Tail) to the east. Between these two halves lies the constellation of Ophiuchus, the ""Serpent-Bearer"". In figurative representations, the body of the serpent is represented as passing behind Ophiuchus between Mu Serpentis in Serpens Caput and Nu Serpentis in Serpens Cauda.The brightest star in Serpens is the red giant star Alpha Serpentis, or Unukalhai, in Serpens Caput, with an apparent magnitude of 2.63. Also located in Serpens Caput are the naked-eye globular cluster Messier 5 and the naked-eye variables R Serpentis and Tau4 Serpentis. Notable extragalactic objects include Seyfert's Sextet, one of the densest galaxy clusters known; Arp 220, the prototypical ultraluminous infrared galaxy; and Hoag's Object, the most famous of the very rare class of galaxies known as ring galaxies.Part of the Milky Way's galactic plane passes through Serpens Cauda, which is therefore rich in galactic deep-sky objects, such as the Eagle Nebula (IC 4703) and its associated star cluster Messier 16. The nebula measures 70 light-years by 50 light-years and contains the Pillars of Creation, three dust clouds that became famous for the image taken by the Hubble Space Telescope. Other striking objects include the Red Square Nebula, one of the few objects in astronomy to take on a square shape; and Westerhout 40, a massive nearby star-forming region consisting of a molecular cloud and an H II region.