Elliptical galaxies
... •The spectrum of an E galaxy resembles that of a K giant star. •E galaxies appear generally red: •very few stars made in the last 1-2 Gyr (recall that after 1 Gyr, only stars with masses < 2 M¯ are still on the main sequence) •Most of the light is emitted while stars are on the giant branch •The sta ...
... •The spectrum of an E galaxy resembles that of a K giant star. •E galaxies appear generally red: •very few stars made in the last 1-2 Gyr (recall that after 1 Gyr, only stars with masses < 2 M¯ are still on the main sequence) •Most of the light is emitted while stars are on the giant branch •The sta ...
Beasts of the Southern Wild: Discovery of nine Ultra Faint satellites
... established with the DES data alone. Based on the morphological properties, three of the new satellites are dwarf galaxies, one of which is located at the very outskirts of the Milky Way, at a distance of 380 kpc. The remaining 6 objects have sizes and luminosities comparable to the Segue 1 satellit ...
... established with the DES data alone. Based on the morphological properties, three of the new satellites are dwarf galaxies, one of which is located at the very outskirts of the Milky Way, at a distance of 380 kpc. The remaining 6 objects have sizes and luminosities comparable to the Segue 1 satellit ...
Interpretation of the Helix Planetary Nebula using Hydro
... Clumps of collisionless or collisional CDM would either form black holes or thermalize in time periods of order the gravitational free fall time (ρG)−1/2 because the particles would gravitate to the center of the clump by core collapse where the density would exponentiate, causing double and triple ...
... Clumps of collisionless or collisional CDM would either form black holes or thermalize in time periods of order the gravitational free fall time (ρG)−1/2 because the particles would gravitate to the center of the clump by core collapse where the density would exponentiate, causing double and triple ...
WFIRST-2.4: What Every Astronomer Should Know
... Euclid weak lensing survey uses a wide optical filter and reaches an AB-magnitude depth similar to what LSST achieves in each of its g, r, and i filters. The cumulative imaging depth in the WFIRST-2.4 supernova survey fields, which will be observed many times over a 2-year interval, reaches 0.5 – 2. ...
... Euclid weak lensing survey uses a wide optical filter and reaches an AB-magnitude depth similar to what LSST achieves in each of its g, r, and i filters. The cumulative imaging depth in the WFIRST-2.4 supernova survey fields, which will be observed many times over a 2-year interval, reaches 0.5 – 2. ...
Chemical Signatures in Dwarf Galaxies
... related to one another raises an interesting series of questions. Are dwarf gal axies related to protogalactic fragments, the low mass systems that formed in a L Cold Dark Matter (LCDM) Universe that later merged to build up the large spirals that we see today? Are the dwarf spheroidal and Sloan ga ...
... related to one another raises an interesting series of questions. Are dwarf gal axies related to protogalactic fragments, the low mass systems that formed in a L Cold Dark Matter (LCDM) Universe that later merged to build up the large spirals that we see today? Are the dwarf spheroidal and Sloan ga ...
astronomy advisory panel strategy
... (e-MERLIN, SKA – mapping HI from reionisation to the present). Underlying the push to observe normal galaxies throughout their lives will be studies of comparator nearby galaxies and extensive theoretical modelling of galactic evolution. Wide-field surveys will generate the huge samples needed for s ...
... (e-MERLIN, SKA – mapping HI from reionisation to the present). Underlying the push to observe normal galaxies throughout their lives will be studies of comparator nearby galaxies and extensive theoretical modelling of galactic evolution. Wide-field surveys will generate the huge samples needed for s ...
Collapse: Method 2
... Molecular clouds are cold: 8<= Tkin<=20 K Typical value ~10 K Low ionization: fe =ne/n ~10-6 - 10-7 => very neutral! High density: n(H2) >= 100 cm-3 Giant molecular clouds are very massive: M~ 104 to 106 solar masses Giant molecular clouds are large: size ~ 100 parsecs They are clumpy Supersonic gas ...
... Molecular clouds are cold: 8<= Tkin<=20 K Typical value ~10 K Low ionization: fe =ne/n ~10-6 - 10-7 => very neutral! High density: n(H2) >= 100 cm-3 Giant molecular clouds are very massive: M~ 104 to 106 solar masses Giant molecular clouds are large: size ~ 100 parsecs They are clumpy Supersonic gas ...
In Pursuit of the Least Luminous Galaxies
... the most direct measurement of the mass spectrum, spatial distribution, and clustering scale of dark matter. What was initially viewed as a problem now provides an opportunity to simultaneously learn about dark matter and galaxy formation physics. Many studies have invoked simple models of galaxy fo ...
... the most direct measurement of the mass spectrum, spatial distribution, and clustering scale of dark matter. What was initially viewed as a problem now provides an opportunity to simultaneously learn about dark matter and galaxy formation physics. Many studies have invoked simple models of galaxy fo ...
Spectroscopic confirmation of a galaxy at redshift z=8.6
... continuum flux density and Lya flux of UDFy-38135539. The uncertainties in this data are shown in the inset (the 1s random uncertainty and the systematic uncertainty added in quadrature). The uncertainty in the Lya flux is dominated by the systematic uncertainties, which are included in the error ba ...
... continuum flux density and Lya flux of UDFy-38135539. The uncertainties in this data are shown in the inset (the 1s random uncertainty and the systematic uncertainty added in quadrature). The uncertainty in the Lya flux is dominated by the systematic uncertainties, which are included in the error ba ...
ASTR-264-Lecture
... Review: over a period of 10 weeks, Mars appears to stop, back up, then go forward Most advanced geocentric model was that of Ptolemy (100-170), the Ptolemaic Model: Accurate enough to be used for 1500 years Arabic translation of Ptolemy’s work named Almagest (greatest compilation) He does have plane ...
... Review: over a period of 10 weeks, Mars appears to stop, back up, then go forward Most advanced geocentric model was that of Ptolemy (100-170), the Ptolemaic Model: Accurate enough to be used for 1500 years Arabic translation of Ptolemy’s work named Almagest (greatest compilation) He does have plane ...
CHEMICAL ABUNDANCE DISTRIBUTIONS OF GALACTIC HALOS
... prescription (see Robertson et al. 2005 and x 2.2 for more details). Star formation ceases soon after accretion onto the main halo, as it is assumed that the gas is lost at that point due to ram pressure stripping. The free parameters in this model are fully constrained by requiring that it approxim ...
... prescription (see Robertson et al. 2005 and x 2.2 for more details). Star formation ceases soon after accretion onto the main halo, as it is assumed that the gas is lost at that point due to ram pressure stripping. The free parameters in this model are fully constrained by requiring that it approxim ...
Disk Instability Models
... Heretical Explanation for Microlensing Planets • Most stars form in regions of high-mass star formation (e.g., Orion, Carina) where their protoplanetary disks can be photoevaporated away by nearby O stars. • Photoevaporation converts gas giant protoplanets into ice giants if the protoplanet orbit ...
... Heretical Explanation for Microlensing Planets • Most stars form in regions of high-mass star formation (e.g., Orion, Carina) where their protoplanetary disks can be photoevaporated away by nearby O stars. • Photoevaporation converts gas giant protoplanets into ice giants if the protoplanet orbit ...
Corrugations in the Disk of the Edge
... stellar populations traced by the mid-infrared light. This suggests that the process leading to the vertical displacements may be linked with the regulation of star formation in the galaxy. We have also identified a relationship between the ...
... stellar populations traced by the mid-infrared light. This suggests that the process leading to the vertical displacements may be linked with the regulation of star formation in the galaxy. We have also identified a relationship between the ...
MOLECULAR CLOUDS 1. Introduction
... cannot have been a factor in their formation. Is gravity important only in forming clouds that exceed a certain minimum mass? Mechanisms proposed for molecular cloud formation can be divided into three general categories: collisional agglomeration of smaller clouds (e.g. Kwan 1979 Scoville & Hersh ...
... cannot have been a factor in their formation. Is gravity important only in forming clouds that exceed a certain minimum mass? Mechanisms proposed for molecular cloud formation can be divided into three general categories: collisional agglomeration of smaller clouds (e.g. Kwan 1979 Scoville & Hersh ...
Genesis of the Heaviest Elements in the Milky Way Galaxy
... capture elements are below the solar levels, the -capture element abundances in this star are the same as the solar system elemental -process-only abundances. This similarity in abundance levels has now been observed in several other halo stars (17). There is an additional, apparently rare, anom ...
... capture elements are below the solar levels, the -capture element abundances in this star are the same as the solar system elemental -process-only abundances. This similarity in abundance levels has now been observed in several other halo stars (17). There is an additional, apparently rare, anom ...
REVIEWS The formation of the first stars and galaxies Volker Bromm
... first sources of light and chemical elements beyond the primordial hydrogen and helium produced in the Big Bang. The interplay of theory and upcoming observations promises to answer the key open questions in this emerging field. he formation of the first stars and galaxies at the end of the cosmic ‘ ...
... first sources of light and chemical elements beyond the primordial hydrogen and helium produced in the Big Bang. The interplay of theory and upcoming observations promises to answer the key open questions in this emerging field. he formation of the first stars and galaxies at the end of the cosmic ‘ ...
ASTR 1101-001 Spring 2008 - Louisiana State University
... • Astronomers are convinced that the gas making up the Crab Nebula is (what is left of) the outermost layers of a massive star that died violently (a “supernova explosion”) in the year 1054, and that its central pulsar is a rapidly rotating neutron star – a compact stellar remnant, which was once th ...
... • Astronomers are convinced that the gas making up the Crab Nebula is (what is left of) the outermost layers of a massive star that died violently (a “supernova explosion”) in the year 1054, and that its central pulsar is a rapidly rotating neutron star – a compact stellar remnant, which was once th ...
129 DYNAMICAL STREAMS IN THE SOLAR NEIGHBOURHOOD B
... alone is not sufficient to create the observed streams. Nevertheless, De Simone et al. (2004) have shown that the structure of the local distribution function could well be due to a lumpy potential related to the presence of strong transient spiral waves. Besides those simulations, a recent model of ...
... alone is not sufficient to create the observed streams. Nevertheless, De Simone et al. (2004) have shown that the structure of the local distribution function could well be due to a lumpy potential related to the presence of strong transient spiral waves. Besides those simulations, a recent model of ...
Galactic chemical evolution of heavy elements: from Barium to
... estimates, but the distribution of neutron exposures can no longer be approximated by an exponential distribution, as commonly assumed previously, with relevant consequences for the dependence of neutron captures on metallicity (Busso et al. 1997). A thorough analysis of the implications of the new ...
... estimates, but the distribution of neutron exposures can no longer be approximated by an exponential distribution, as commonly assumed previously, with relevant consequences for the dependence of neutron captures on metallicity (Busso et al. 1997). A thorough analysis of the implications of the new ...
Introduc on to the Fundamental Astrophysics Course
... between the stars. • The interstellar regions are have very low densi)es and consist mainly of gas (99%) and dust. • In total, approximately 15% of the visible ma]er in the Milky Way is composed ...
... between the stars. • The interstellar regions are have very low densi)es and consist mainly of gas (99%) and dust. • In total, approximately 15% of the visible ma]er in the Milky Way is composed ...
EF Eri: Its White Dwarf Primary and L Dwarf Secondary
... The Optical Spectrum during the LOW STATE: H emission faded quickly after 1997. Five years into the low state, EF Eri’s optical spectrum shows Zeeman split Balmer absorption lines caused by the WD B field and NO emission lines. No secondary star features are detected. Note non-BB WD shape. ...
... The Optical Spectrum during the LOW STATE: H emission faded quickly after 1997. Five years into the low state, EF Eri’s optical spectrum shows Zeeman split Balmer absorption lines caused by the WD B field and NO emission lines. No secondary star features are detected. Note non-BB WD shape. ...
Why are most molecular clouds not gravitationally bound
... 2 S I M U L AT I O N S The calculations presented here are 3D smoothed particle hydrodynamics (SPH) simulations using an SPH code developed by Benz (Benz et al. 1990), Bate (Bate, Bonnell & Price 1995) and Price (Price & Monaghan 2007). The code uses a variable smoothing length, such that the densit ...
... 2 S I M U L AT I O N S The calculations presented here are 3D smoothed particle hydrodynamics (SPH) simulations using an SPH code developed by Benz (Benz et al. 1990), Bate (Bate, Bonnell & Price 1995) and Price (Price & Monaghan 2007). The code uses a variable smoothing length, such that the densit ...
Stars and Galaxies
... shifted towards the red part of the visible spectrum The faster they move away from us, the more they are redshifted. Thus, redshift is a reasonable way to measure the speed of an object. When we observe the redshift of galaxies, almost every galaxy appears to be moving away from us – the Univer ...
... shifted towards the red part of the visible spectrum The faster they move away from us, the more they are redshifted. Thus, redshift is a reasonable way to measure the speed of an object. When we observe the redshift of galaxies, almost every galaxy appears to be moving away from us – the Univer ...