Grand Design and Flocculent Spirals in the Spitzer Survey of Stellar
... stars dominate. The sample includes flocculent, multiple arm, and grand design types with a wide range of Hubble and bar types. We find that most optically flocculent galaxies are also flocculent in the mid-IR because of star formation uncorrelated with stellar density waves, whereas multiple arm an ...
... stars dominate. The sample includes flocculent, multiple arm, and grand design types with a wide range of Hubble and bar types. We find that most optically flocculent galaxies are also flocculent in the mid-IR because of star formation uncorrelated with stellar density waves, whereas multiple arm an ...
X-Ray Astronomy of Supernova Remnants
... These are tips and tricks that you can do to help the students perform this exercise. 1) It may help to divide the class into groups of 2-3 students each. You can then assign to each a single knot to analyze. Once all the groups are done, you can collate the results and share them with the class. Qu ...
... These are tips and tricks that you can do to help the students perform this exercise. 1) It may help to divide the class into groups of 2-3 students each. You can then assign to each a single knot to analyze. Once all the groups are done, you can collate the results and share them with the class. Qu ...
Research paper
... at all orientations from the dynamical ejection center shows similar behavior. The typical radial-velocity gradients range from less than 200 to over 2,000 km s−1 per parsec. In some, such as the 4000 -long streamer shown in lower-right of Figure 5, the line-brightness peaks near the high-velocity e ...
... at all orientations from the dynamical ejection center shows similar behavior. The typical radial-velocity gradients range from less than 200 to over 2,000 km s−1 per parsec. In some, such as the 4000 -long streamer shown in lower-right of Figure 5, the line-brightness peaks near the high-velocity e ...
XRaySNR_sm - Gettysburg College
... We note that the “observed spectra” used in this lab are actually models themselves, based on the physical parameters of the nebula found by Hwang and Laming. The actual spectral data from X-ray observatories are quite noisy and difficult to present, so this method was used instead. The spectra were ...
... We note that the “observed spectra” used in this lab are actually models themselves, based on the physical parameters of the nebula found by Hwang and Laming. The actual spectral data from X-ray observatories are quite noisy and difficult to present, so this method was used instead. The spectra were ...
a changing cosmos - Whittier Union High School District
... is found to be on a collision course with Earth, so that an effort could be made to divert it. Currently, NASA carries out the “Spaceguard Survey” to find NEOs greater than 140 meters in diameter, and this program was budgeted at $4.1 million per year for FY 2006 through FY 2012. In chapter 7, we'll ...
... is found to be on a collision course with Earth, so that an effort could be made to divert it. Currently, NASA carries out the “Spaceguard Survey” to find NEOs greater than 140 meters in diameter, and this program was budgeted at $4.1 million per year for FY 2006 through FY 2012. In chapter 7, we'll ...
Astronomy 250 - University of Victoria
... though a star’s movement across the sky (its proper motion, often given in arcseconds per year) can be measured. Proper motions are generally measured by taking two pictures of a stellar field a few years apart. The change in position and direction of motion of a given star can be determined by meas ...
... though a star’s movement across the sky (its proper motion, often given in arcseconds per year) can be measured. Proper motions are generally measured by taking two pictures of a stellar field a few years apart. The change in position and direction of motion of a given star can be determined by meas ...
Note - HKU Physics
... 5. The star is in local thermodynamic equilibrium (LTE). In other words, every microscopically large but macroscopically small region is very close to and hence can be well approximated by a region in thermodynamic equilibrium. Thus, it makes sense to talk about thermodynamic variables such as tempe ...
... 5. The star is in local thermodynamic equilibrium (LTE). In other words, every microscopically large but macroscopically small region is very close to and hence can be well approximated by a region in thermodynamic equilibrium. Thus, it makes sense to talk about thermodynamic variables such as tempe ...
The Celestial Origin of Atoms
... produced. And thirdly, it attempts to unravel the temporal sequence of the nuclear phenomena that fashion baryonic matter, the stuff of stars and humans, making up the galaxies. Beyond this, it aims to explain the composition of the Solar System and the main trends of chemical evolution in the Galax ...
... produced. And thirdly, it attempts to unravel the temporal sequence of the nuclear phenomena that fashion baryonic matter, the stuff of stars and humans, making up the galaxies. Beyond this, it aims to explain the composition of the Solar System and the main trends of chemical evolution in the Galax ...
Where stars form: inside-out growth and coherent star formation from
... 2676 galaxies enabling a division into subsamples based on stellar mass and star formation rate. By creating deep stacked Hα images, we reach surface brightness limits of 1 × 10−18 erg s−1 cm−2 arcsec−2 , allowing us to map the distribution of ionized gas out to greater than 10 kpc for typical L∗ ga ...
... 2676 galaxies enabling a division into subsamples based on stellar mass and star formation rate. By creating deep stacked Hα images, we reach surface brightness limits of 1 × 10−18 erg s−1 cm−2 arcsec−2 , allowing us to map the distribution of ionized gas out to greater than 10 kpc for typical L∗ ga ...
Preliminary Talk Abstract Book - MoCA
... The Build-up Of The Red Sequence in High Redshift Galaxy Clusters Pierluigi Cerulo, Swinburne University of Technology 12:40pm Monday Clusters of galaxies are the most massive virialised cosmic structures. The diversity of their environmental conditions, from the dense cores to the sparse outskirts ...
... The Build-up Of The Red Sequence in High Redshift Galaxy Clusters Pierluigi Cerulo, Swinburne University of Technology 12:40pm Monday Clusters of galaxies are the most massive virialised cosmic structures. The diversity of their environmental conditions, from the dense cores to the sparse outskirts ...
2. The X-ray-Radio correlation for bulgeless galaxies
... Fig. 20: The bulgeless galaxies detected in the X-ray band by the C-COSMOS survey. The continuous line represents the luminosity detection limit for the survey in respect to the redshift. The dashed line represents the limit above which galaxies are considered AGN................................... ...
... Fig. 20: The bulgeless galaxies detected in the X-ray band by the C-COSMOS survey. The continuous line represents the luminosity detection limit for the survey in respect to the redshift. The dashed line represents the limit above which galaxies are considered AGN................................... ...
a wide-field survey for variable stars
... Tauri variable stars. The nearby dusty, yellow cloud is Hind’s Variable Nebula (NGC 1555/1554). Over 400 light-years away, at the edge of a molecular cloud, both star and nebula are seen to vary significantly in brightness but not necessarily at the same time, adding to the mystery of the intriguing ...
... Tauri variable stars. The nearby dusty, yellow cloud is Hind’s Variable Nebula (NGC 1555/1554). Over 400 light-years away, at the edge of a molecular cloud, both star and nebula are seen to vary significantly in brightness but not necessarily at the same time, adding to the mystery of the intriguing ...
Star Clusters - Caltech Astronomy
... infrared images covering a suitable field of view. While this definition may seem imprecise, it conveniently includes most of those objects (in our Galaxy at least) listed in the existing cluster catalogs. At the same time, it excludes galaxy-sized systems or objects with insignificant numbers of st ...
... infrared images covering a suitable field of view. While this definition may seem imprecise, it conveniently includes most of those objects (in our Galaxy at least) listed in the existing cluster catalogs. At the same time, it excludes galaxy-sized systems or objects with insignificant numbers of st ...
Observational evidence for AGN feedback in early
... activity, black hole activity, the composite of the two and quiescence. We find that emission is mostly LINER (low ionization nuclear emission line region) like in high-mass galaxies (σ > 200 km s−1 ) and roughly evenly distributed between star formation and AGN at intermediate and low (σ < 100 km s ...
... activity, black hole activity, the composite of the two and quiescence. We find that emission is mostly LINER (low ionization nuclear emission line region) like in high-mass galaxies (σ > 200 km s−1 ) and roughly evenly distributed between star formation and AGN at intermediate and low (σ < 100 km s ...
Ch. 20 - Astro1010
... 3rd law. We take the radius of our orbit and the period. Plugging those numbers into Kepler's 3rd law we can estimate the mass inside our orbit. This gives just shy of 100 billion solar masses. Other mass estimates of the Milky Way are up to 1 trillion solar masses. ...
... 3rd law. We take the radius of our orbit and the period. Plugging those numbers into Kepler's 3rd law we can estimate the mass inside our orbit. This gives just shy of 100 billion solar masses. Other mass estimates of the Milky Way are up to 1 trillion solar masses. ...
Plotting the Rotation Curve of M31
... Answer: large collections of stars. They vary in their morphology and stellar composition i.e. ellipticals are red and contain older stars than spirals which are predominantly blue/white in colour and younger. What is a spectrum? Answer: a ‘fingerprint’ of an object made of light. The spectrum of vis ...
... Answer: large collections of stars. They vary in their morphology and stellar composition i.e. ellipticals are red and contain older stars than spirals which are predominantly blue/white in colour and younger. What is a spectrum? Answer: a ‘fingerprint’ of an object made of light. The spectrum of vis ...
IXO as an observatory in the large telescopes era
... holes (>109 M) in the Universe, are extremely rare. Typical AGN, which are of lower luminosity and often obscured, remain largely undiscovered. Uncovering such objects at z=6-7 (and even higher redshifts) holds the key to our understanding of this crucial phase in the development of the Universe. I ...
... holes (>109 M) in the Universe, are extremely rare. Typical AGN, which are of lower luminosity and often obscured, remain largely undiscovered. Uncovering such objects at z=6-7 (and even higher redshifts) holds the key to our understanding of this crucial phase in the development of the Universe. I ...
Article PDF - IOPscience
... Received 2009 December 22; accepted 2010 March 11; published 2010 April 5 ...
... Received 2009 December 22; accepted 2010 March 11; published 2010 April 5 ...
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 ...
thick disk - asteroSTEP
... Chemical studies of the old disk stars in the Galaxy can help to identify disk stars that are the debris of common dispersed star-forming aggregates. Chemical tagging will work if • stars form in large aggregates - believed to be true • aggregates are chemically homogenous • aggregates have unique ...
... Chemical studies of the old disk stars in the Galaxy can help to identify disk stars that are the debris of common dispersed star-forming aggregates. Chemical tagging will work if • stars form in large aggregates - believed to be true • aggregates are chemically homogenous • aggregates have unique ...
Notes on Stars
... of the Balmer line strengths along the Harvard sequence? As the excitation occurs from the n = 2 state, the temperature has to be high enough to populate this level. This is the case for most of the stars. The n = 2 level will become more and more populated if we pass from K stars to A stars, as wit ...
... of the Balmer line strengths along the Harvard sequence? As the excitation occurs from the n = 2 state, the temperature has to be high enough to populate this level. This is the case for most of the stars. The n = 2 level will become more and more populated if we pass from K stars to A stars, as wit ...
A Wide-Field Study of the z~ 0.8 Cluster RX J0152. 7
... z = 0.834 cluster RX J0152.7-1357 (hereafter RX J015213) and its outskirts. This is a very rich cluster with extensive imaging and spectroscopic datasets that now cover a very wide area (out to ∼ 6 Mpc in radius). As such it is an ideal target for a study of galaxy evolution and transformation over ...
... z = 0.834 cluster RX J0152.7-1357 (hereafter RX J015213) and its outskirts. This is a very rich cluster with extensive imaging and spectroscopic datasets that now cover a very wide area (out to ∼ 6 Mpc in radius). As such it is an ideal target for a study of galaxy evolution and transformation over ...
The spectroscopic Hertzsprung-Russell diagram
... Methods. Our spectroscopic Hertzsprung-Russell (sHR) diagram shows the inverse of the flux-mean gravity versus the effective temperature. Observed stars whose spectra have been quantitatively analyzed can be entered in this diagram without the knowledge of the stellar distance or absolute brightness ...
... Methods. Our spectroscopic Hertzsprung-Russell (sHR) diagram shows the inverse of the flux-mean gravity versus the effective temperature. Observed stars whose spectra have been quantitatively analyzed can be entered in this diagram without the knowledge of the stellar distance or absolute brightness ...
Chapter 14 Black Holes as Central Engines
... 14.4 Jets and Magnetic Fields A magnetic field cannot be anchored to the black hole itself because the event horizon pinches off any magnetic field lines that cross it. • However, the whirling plasma of the accretion disk lies outside the event horizon and it could have a strong magnetic field. • Th ...
... 14.4 Jets and Magnetic Fields A magnetic field cannot be anchored to the black hole itself because the event horizon pinches off any magnetic field lines that cross it. • However, the whirling plasma of the accretion disk lies outside the event horizon and it could have a strong magnetic field. • Th ...
Galaxy morphology, luminosity, and environment in the SDSS DR7
... and blue) using data from the Sloan Digital Sky Survey (SDSS), correcting the luminosities for the intrinsic absorption. We use the global luminosity density field to define different environments, and analyse the environmental dependence of galaxy morphology and colour. The smoothed bootstrap method ...
... and blue) using data from the Sloan Digital Sky Survey (SDSS), correcting the luminosities for the intrinsic absorption. We use the global luminosity density field to define different environments, and analyse the environmental dependence of galaxy morphology and colour. The smoothed bootstrap method ...
H II region
An H II region is a large, low-density cloud of partially ionized gas in which star formation has recently taken place. The short-lived blue stars forged in these regions emit copious amounts of ultraviolet light that ionize the surrounding gas. H II regions—sometimes several hundred light-years across—are often associated with giant molecular clouds. The first known H II region was the Orion Nebula, which was discovered in 1610 by Nicolas-Claude Fabri de Peiresc.H II regions are named for the large amount of ionised atomic hydrogen they contain, referred to as H II, pronounced H-two by astronomers (an H I region being neutral atomic hydrogen, and H2 being molecular hydrogen). Such regions have extremely diverse shapes, because the distribution of the stars and gas inside them is irregular. They often appear clumpy and filamentary, sometimes showing bizarre shapes such as the Horsehead Nebula. H II regions may give birth to thousands of stars over a period of several million years. In the end, supernova explosions and strong stellar winds from the most massive stars in the resulting star cluster will disperse the gases of the H II region, leaving behind a cluster of birthed stars such as the Pleiades.H II regions can be seen to considerable distances in the universe, and the study of extragalactic H II regions is important in determining the distance and chemical composition of other galaxies. Spiral and irregular galaxies contain many H II regions, while elliptical galaxies are almost devoid of them. In the spiral galaxies, including the Milky Way, H II regions are concentrated in the spiral arms, while in the irregular galaxies they are distributed chaotically. Some galaxies contain huge H II regions, which may contain tens of thousands of stars. Examples include the 30 Doradus region in the Large Magellanic Cloud and NGC 604 in the Triangulum Galaxy.