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Improving Galactic Center Astrometry by Reducing the Effects of
... We present significantly improved proper motion measurements of the Milky Way’s central stellar cluster. These improvements are made possible by refining our astrometric reference frame with a new geometric optical distortion model for the W. M. Keck II 10 m telescope’s Adaptive Optics camera (NIRC2 ...
... We present significantly improved proper motion measurements of the Milky Way’s central stellar cluster. These improvements are made possible by refining our astrometric reference frame with a new geometric optical distortion model for the W. M. Keck II 10 m telescope’s Adaptive Optics camera (NIRC2 ...
the reality of the wolf 630 moving group - TigerPrints
... The concept of relic kinematic assemblages from dispersed stellar clusters has remained contentious since Eggen’s initial formulation of moving groups in the 1960’s. However, the availability of high quality parallaxes from the Hipparcos space astrometry mission has resulted in distance measurements ...
... The concept of relic kinematic assemblages from dispersed stellar clusters has remained contentious since Eggen’s initial formulation of moving groups in the 1960’s. However, the availability of high quality parallaxes from the Hipparcos space astrometry mission has resulted in distance measurements ...
Tuomas Kangas
... Different ways to gain information on the progenitor stars of core-collapse supernovae are explored, with an emphasis on using the environments of supernovae. In the articles included in the thesis, various such methods are demonstrated and utilized to constrain the progenitor stars of different typ ...
... Different ways to gain information on the progenitor stars of core-collapse supernovae are explored, with an emphasis on using the environments of supernovae. In the articles included in the thesis, various such methods are demonstrated and utilized to constrain the progenitor stars of different typ ...
- Durham Research Online
... galaxies are classified into quenched, moderately star-forming, and strongly star-forming using a combination of spectral features and far-UV-to-optical colors; this approach optimally distinguishes quenched systems from dust-reddened star-forming galaxies. The latter contribute up to 50% to the (B ...
... galaxies are classified into quenched, moderately star-forming, and strongly star-forming using a combination of spectral features and far-UV-to-optical colors; this approach optimally distinguishes quenched systems from dust-reddened star-forming galaxies. The latter contribute up to 50% to the (B ...
Submillimeter Array 12CO (2-1) Imaging of the NGC
... density and velocity dispersion (see their Figure 3). As suggested by Meier & Turner (2004), molecular clouds in the nucleus of NGC 6946 are likely influenced by the nuclear bar and therefore have peculiar CO line ratios. In Figure 4, we show GMC properties as a function of the galactocentric radius ...
... density and velocity dispersion (see their Figure 3). As suggested by Meier & Turner (2004), molecular clouds in the nucleus of NGC 6946 are likely influenced by the nuclear bar and therefore have peculiar CO line ratios. In Figure 4, we show GMC properties as a function of the galactocentric radius ...
Evidence of suppression of star formation by quasar
... UKIRT Infrared Deep Sky Survey (UKIDSS, Lawrence et al. 2007) is a near-IR sky survey using WFCAM on the UK Infrared Telescope (UKIRT, Casali et al. 2007) in Hawaii, that surveyed about 7500 deg2 of the Northern Sky and is often considered to be the near-IR counterpart of the SDSS. We use the UKIDSS ...
... UKIRT Infrared Deep Sky Survey (UKIDSS, Lawrence et al. 2007) is a near-IR sky survey using WFCAM on the UK Infrared Telescope (UKIRT, Casali et al. 2007) in Hawaii, that surveyed about 7500 deg2 of the Northern Sky and is often considered to be the near-IR counterpart of the SDSS. We use the UKIDSS ...
Properties of White Dwarfs, Teacher Guide
... Astronomers measure brightness in units of magnitudes: the fainter the object, the larger the magnitude. For instance, our Sun’s apparent magnitude is –26, while the faintest stars you can see in the sky without optical aid is +6. For a difference of 5 magnitudes, the flux changes by a factor of 100 ...
... Astronomers measure brightness in units of magnitudes: the fainter the object, the larger the magnitude. For instance, our Sun’s apparent magnitude is –26, while the faintest stars you can see in the sky without optical aid is +6. For a difference of 5 magnitudes, the flux changes by a factor of 100 ...
The KMOS Redshift One Spectroscopic Survey
... high redshift galaxies with much greater efficiency. KMOS allows for simultaneous observations with up to 24 IFUs within a 7.2 arcminute diameter radius and is thus perfectly suited to such a task. The KMOS Redshift One Spectroscopic Survey (KROSS) is a European Southern Observatory (ESO) guaranteed ...
... high redshift galaxies with much greater efficiency. KMOS allows for simultaneous observations with up to 24 IFUs within a 7.2 arcminute diameter radius and is thus perfectly suited to such a task. The KMOS Redshift One Spectroscopic Survey (KROSS) is a European Southern Observatory (ESO) guaranteed ...
Link
... most massive members have later spectral types can identify locales where stars formed more than 40 Myr ago. The mass spectra, locations, velocities, and ages of young stars and the properties of gas in nearby associations provide clues about the history of star formation and the origin, evolution, ...
... most massive members have later spectral types can identify locales where stars formed more than 40 Myr ago. The mass spectra, locations, velocities, and ages of young stars and the properties of gas in nearby associations provide clues about the history of star formation and the origin, evolution, ...
Rotation Curves of Spiral Galaxies
... nebula the ratio f of mass density to light density is found to be very high; and this conclusion holds for whatever dynamical model we consider. The spectrum of the nebula shows the characteristics of G-type dwarfs. Since f cannot be much larger than 1 for such stars, they can account for roughly o ...
... nebula the ratio f of mass density to light density is found to be very high; and this conclusion holds for whatever dynamical model we consider. The spectrum of the nebula shows the characteristics of G-type dwarfs. Since f cannot be much larger than 1 for such stars, they can account for roughly o ...
The Green Valley is a Red Herring: Galaxy Zoo reveals two
... We use SDSS+GALEX+Galaxy Zoo data to study the quenching of star formation in lowredshift galaxies. We show that the green valley between the blue cloud of star-forming galaxies and the red sequence of quiescent galaxies in the colour-mass diagram is not a single transitional state through which mos ...
... We use SDSS+GALEX+Galaxy Zoo data to study the quenching of star formation in lowredshift galaxies. We show that the green valley between the blue cloud of star-forming galaxies and the red sequence of quiescent galaxies in the colour-mass diagram is not a single transitional state through which mos ...
Binary progenitor models of type IIb supernovae
... rate indicated by observations. It is larger but still comparable to the rate expected from massive single stars. We evaluate extensively the effect of various assumptions such as the adopted accretion efficiency, the binary fraction and distributions for the initial binary parameters. To recover th ...
... rate indicated by observations. It is larger but still comparable to the rate expected from massive single stars. We evaluate extensively the effect of various assumptions such as the adopted accretion efficiency, the binary fraction and distributions for the initial binary parameters. To recover th ...
TYPE II SUPERNOVAE AS DISTANCE INDICATORS by Mario
... Enrico Capallaro, and Massimo Turatto, for allowing me to use their spectra and photometry obtained in the course of the ESO Supernova Key Project, and from Mark Phillips and Sofia Kirhakos for making available their extensive dataset of SN 1986L. A special thank must go to Ron Eastman for providing ...
... Enrico Capallaro, and Massimo Turatto, for allowing me to use their spectra and photometry obtained in the course of the ESO Supernova Key Project, and from Mark Phillips and Sofia Kirhakos for making available their extensive dataset of SN 1986L. A special thank must go to Ron Eastman for providing ...
An Improved Distance and Mass Estimate for Sgr A* from a Multistar
... before applying speckle holography as was done in the original SAA analysis. This is the first complete application of speckle holography to the Galactic Center speckle imaging data set from Keck Observatory. After the final speckle holography images are constructed for each observation epoch, an in ...
... before applying speckle holography as was done in the original SAA analysis. This is the first complete application of speckle holography to the Galactic Center speckle imaging data set from Keck Observatory. After the final speckle holography images are constructed for each observation epoch, an in ...
GOODS: Great Observatories Origins Deep Survey
... Some rates are relatively low, ~ today’s spirals; others are prodigiously high Metallicity ~1/10 to ~ solar Still an open issue ...
... Some rates are relatively low, ~ today’s spirals; others are prodigiously high Metallicity ~1/10 to ~ solar Still an open issue ...
Giant Molecular Clouds in Local Group Galaxies
... Solomon et al. (1987) in our plots, but we do make comparisons to their work at the end of this section. Except where noted, we consider only clouds that are well-resolved by the telescope beam; the GMCs must have angular diameters at least twice that of the beam used to observe them. Are we seeing ...
... Solomon et al. (1987) in our plots, but we do make comparisons to their work at the end of this section. Except where noted, we consider only clouds that are well-resolved by the telescope beam; the GMCs must have angular diameters at least twice that of the beam used to observe them. Are we seeing ...
Star Formation in the Milky Way and Nearby Galaxies Further
... galaxy formation and evolution, however, it is also a subject at the root of astrophysics on its largest scales. The past decade has witnessed an unprecedented stream of new observational information on star formation on all scales, thanks in no small part to new facilities such as the Galaxy Evolut ...
... galaxy formation and evolution, however, it is also a subject at the root of astrophysics on its largest scales. The past decade has witnessed an unprecedented stream of new observational information on star formation on all scales, thanks in no small part to new facilities such as the Galaxy Evolut ...
Carbon-enhanced metal-poor stars: a window on AGB
... Many of the carbon-enhanced metal-poor (CEMP) stars that we observe in the Galactic halo are found in binary systems and show enhanced abundances of elements produced by the slow neutron-capture process (s-elements). The origin of the peculiar chemical abundances of these CEMP-s stars is believed to ...
... Many of the carbon-enhanced metal-poor (CEMP) stars that we observe in the Galactic halo are found in binary systems and show enhanced abundances of elements produced by the slow neutron-capture process (s-elements). The origin of the peculiar chemical abundances of these CEMP-s stars is believed to ...
Slide 1
... protoplanetary disk at a distance of 150 pc (roughly, the distance of the starforming clouds in Ophiuchus or Corona Australis), enabling one to study the physical, chemical, and magnetic field structure of the disk and to detect the tidal gaps created by planets undergoing formation. The ability t ...
... protoplanetary disk at a distance of 150 pc (roughly, the distance of the starforming clouds in Ophiuchus or Corona Australis), enabling one to study the physical, chemical, and magnetic field structure of the disk and to detect the tidal gaps created by planets undergoing formation. The ability t ...
Chemical gradients in the Milky Way from the RAVE data
... With these data we determined Galactocentric positions and absolute velocities. Galactic orbital parameters such as the guiding radius (Rg ) and maximum distance from the Galactic plane (Zmax ) were considered and computed as explained in Sect. 3.1. In this first paper we limit our investigation to ...
... With these data we determined Galactocentric positions and absolute velocities. Galactic orbital parameters such as the guiding radius (Rg ) and maximum distance from the Galactic plane (Zmax ) were considered and computed as explained in Sect. 3.1. In this first paper we limit our investigation to ...
Stellar Mass Loss in Globular - Jodrell Bank Centre for Astrophysics
... A thesis is impossible without the help of others. Most notably, that help came from my supervisor, Jacco van Loon (JvL), who gave backing to my findings, and who assisted with both scientific theory and practise. Similarly, thanks to my colleagues at Keele for all the minutiae: from shell scripting t ...
... A thesis is impossible without the help of others. Most notably, that help came from my supervisor, Jacco van Loon (JvL), who gave backing to my findings, and who assisted with both scientific theory and practise. Similarly, thanks to my colleagues at Keele for all the minutiae: from shell scripting t ...
betelgeuse and the red supergiants
... rotation, binarity, et cetera. We must judge how typical or peculiar Betelgeuse is, by comparison with other stars with the same birth mass, composition, rotation, binarity, et cetera. Because red supergiants are rare, and generally fairly distant, we lack samples with all of the above properties kn ...
... rotation, binarity, et cetera. We must judge how typical or peculiar Betelgeuse is, by comparison with other stars with the same birth mass, composition, rotation, binarity, et cetera. Because red supergiants are rare, and generally fairly distant, we lack samples with all of the above properties kn ...
A FUSE Survey of Coronal Forbidden Lines in Late
... the active spectra can be identified because they will be relatively narrow and also present in the inactive stars. The underlying assumptions in this comparative analysis are that active stars have larger coronal emission measures than inactive stars, that giant stars all have reasonably similar emi ...
... the active spectra can be identified because they will be relatively narrow and also present in the inactive stars. The underlying assumptions in this comparative analysis are that active stars have larger coronal emission measures than inactive stars, that giant stars all have reasonably similar emi ...
RADIO OBSERVATIONS RELATED TO STAR FORMATION P. G.
... central part of the nuclear disk, < 200 pc from the nucleus of our Galaxy. A large number of small HII regions are located between the main spiral arms, and are often associated with dense clouds (CO-clouds). These small HII regions represent Ο star formation in the interarm region. By counting Lyma ...
... central part of the nuclear disk, < 200 pc from the nucleus of our Galaxy. A large number of small HII regions are located between the main spiral arms, and are often associated with dense clouds (CO-clouds). These small HII regions represent Ο star formation in the interarm region. By counting Lyma ...
Cosmic distance ladder
The cosmic distance ladder (also known as the extragalactic distance scale) is the succession of methods by which astronomers determine the distances to celestial objects. A real direct distance measurement of an astronomical object is possible only for those objects that are ""close enough"" (within about a thousand parsecs) to Earth. The techniques for determining distances to more distant objects are all based on various measured correlations between methods that work at close distances and methods that work at larger distances. Several methods rely on a standard candle, which is an astronomical object that has a known luminosity.The ladder analogy arises because no one technique can measure distances at all ranges encountered in astronomy. Instead, one method can be used to measure nearby distances, a second can be used to measure nearby to intermediate distances, and so on. Each rung of the ladder provides information that can be used to determine the distances at the next higher rung.