THE INFLUENCE OF ENVIRONMENTAL EFFECTS ON GALAXY
... Although I have treated the above discussion as applying to early-type galaxies generally, it strictly applies only to the galaxies in the central parts of clusters. Nevertheless, these samples must include some galaxies that are traversing the cluster core for the rst time, and galaxies that appea ...
... Although I have treated the above discussion as applying to early-type galaxies generally, it strictly applies only to the galaxies in the central parts of clusters. Nevertheless, these samples must include some galaxies that are traversing the cluster core for the rst time, and galaxies that appea ...
Document
... of High-z Quasars • Probing dust and star formation in the most massive high-z galaxy • Using IRAM and SCUBA: ~40% of radio-quiet quasars at z>4 detected at 1mm (observed frame) at 1mJy level • Combination of cm and submm submm radiation in radio-quiet quasars come from thermal dust with mass ~ 10 ...
... of High-z Quasars • Probing dust and star formation in the most massive high-z galaxy • Using IRAM and SCUBA: ~40% of radio-quiet quasars at z>4 detected at 1mm (observed frame) at 1mJy level • Combination of cm and submm submm radiation in radio-quiet quasars come from thermal dust with mass ~ 10 ...
ch20
... • How do distance measurements tell us the age of the universe? – Measuring a galaxy's distance and speed allows us to figure out how long the galaxy took to reach its current distance. – Measuring Hubble's constant tells us that amount of time: about 14 billion years. • How does the universe's expa ...
... • How do distance measurements tell us the age of the universe? – Measuring a galaxy's distance and speed allows us to figure out how long the galaxy took to reach its current distance. – Measuring Hubble's constant tells us that amount of time: about 14 billion years. • How does the universe's expa ...
MOND as an alternative to dark matter: the Bullet
... • Matter power spectrum ok without DM (Dodelson & Liguori 2006), but IN THE PRESENT MODEL needs DM in the form of e.g. 2eV neutrinos to fit the angular power spectrum of the CMB, in order not to change the angular-distance relation by having too much acceleration (Skordis et al. 2006) ...
... • Matter power spectrum ok without DM (Dodelson & Liguori 2006), but IN THE PRESENT MODEL needs DM in the form of e.g. 2eV neutrinos to fit the angular power spectrum of the CMB, in order not to change the angular-distance relation by having too much acceleration (Skordis et al. 2006) ...
Galaxy properties
... What is interesting from the cosmological point of view are not simply the properties of single galaxies, but common relations between these properties. Looking for relations between different galaxy properties, like luminosities, sizes, velocity dispersion of stars in them, surface brightnesses, mo ...
... What is interesting from the cosmological point of view are not simply the properties of single galaxies, but common relations between these properties. Looking for relations between different galaxy properties, like luminosities, sizes, velocity dispersion of stars in them, surface brightnesses, mo ...
IAC_L1_intro
... gas in an isolated dark halo : includes star formation and feedback. The break is seeded by rapid radial decrease in surface density of cool gas : break forms within 1 Gyr and gradually moves outwards as the disk grows. The outer exponential is fed by secularly redistributed stars from inner regions ...
... gas in an isolated dark halo : includes star formation and feedback. The break is seeded by rapid radial decrease in surface density of cool gas : break forms within 1 Gyr and gradually moves outwards as the disk grows. The outer exponential is fed by secularly redistributed stars from inner regions ...
What Drives the Stellar Mass Growth of Early-Type
... galactic density (ρ) and low velocity dispersion (σ). The Hickson sample (Hickson 1982), representative of these systems in the nearby Universe (zmed ∼ 0.03), was extensively studied in the last 30 years. More recently, with the advent of high-quality and homogeneous data from SDSS, new CG samples w ...
... galactic density (ρ) and low velocity dispersion (σ). The Hickson sample (Hickson 1982), representative of these systems in the nearby Universe (zmed ∼ 0.03), was extensively studied in the last 30 years. More recently, with the advent of high-quality and homogeneous data from SDSS, new CG samples w ...
The oxygen abundance deficiency in irregular galaxies
... the durations are equal. The values −1 < c < 0 corresponds to shorter epochs with active star formation. This case will be referred to as a “bursting” star formation history. The case with c = –0.75, τ = 13 Gyr, t0 = 0, and n = 7 is shown in Fig.2. The values 0 < c < 1 corresponds to the opposite ca ...
... the durations are equal. The values −1 < c < 0 corresponds to shorter epochs with active star formation. This case will be referred to as a “bursting” star formation history. The case with c = –0.75, τ = 13 Gyr, t0 = 0, and n = 7 is shown in Fig.2. The values 0 < c < 1 corresponds to the opposite ca ...
active galactic nuclei (AGNs) between two BOSS
... forming galaxies and AGNs. The CMASS sample seriously suffers from the radial selection effect, even within the redshift 0.44 ≤ z ≤ 0.6, which will lead to statistical conclusions in the CMASS sample being less likely robust. In the LOWZ sample, the fraction of star-forming galaxies is nearly consta ...
... forming galaxies and AGNs. The CMASS sample seriously suffers from the radial selection effect, even within the redshift 0.44 ≤ z ≤ 0.6, which will lead to statistical conclusions in the CMASS sample being less likely robust. In the LOWZ sample, the fraction of star-forming galaxies is nearly consta ...
Gravitational Waves from Massive Black
... density of local SMBHs. • Most GWBG power comes from z<1-2. ...
... density of local SMBHs. • Most GWBG power comes from z<1-2. ...
MOND
... Apparently contain more matter than is visible (Dark Matter). Alternative Explanation: Modification of Gravity (MOND) MOND describes galactic rotation curves very well. MOND provides predictions verified by observations. Just like Newton‘s Gravity, MOND cannot explain relativististic effects. ...
... Apparently contain more matter than is visible (Dark Matter). Alternative Explanation: Modification of Gravity (MOND) MOND describes galactic rotation curves very well. MOND provides predictions verified by observations. Just like Newton‘s Gravity, MOND cannot explain relativististic effects. ...
Die Sonne im Röntgenlicht
... • NFW Dark matter halo + stellar bulge • Energy and mass input follows the stellar light distribution • CIE plasma emission • Implemented in XSPEC for both projected spectral and radial surface brightness analyses Li & Wang 2005 ...
... • NFW Dark matter halo + stellar bulge • Energy and mass input follows the stellar light distribution • CIE plasma emission • Implemented in XSPEC for both projected spectral and radial surface brightness analyses Li & Wang 2005 ...
CMB-Wed-Crittenden
... We can calculate the amplitude of the signal for size estimator for convergence, using Euclid-like observations. For such a deep survey, the intrinsic-intrinsic correlations are suppressed. However, the cross correlation between lensing and intrinsic signals is still significant, as large as 30% on ...
... We can calculate the amplitude of the signal for size estimator for convergence, using Euclid-like observations. For such a deep survey, the intrinsic-intrinsic correlations are suppressed. However, the cross correlation between lensing and intrinsic signals is still significant, as large as 30% on ...
How different was the Universe at z=1?
... strong luminosity evolution ΔMI ~ -1.2±0.3 while the luminosity of large rotators is seen to remain constant over cosmic time - We conclude that the corresponding strong/weak evolution in galaxy surface brightness is entirely due to a strong/weak luminosity evolution since z=1. This study thus rules ...
... strong luminosity evolution ΔMI ~ -1.2±0.3 while the luminosity of large rotators is seen to remain constant over cosmic time - We conclude that the corresponding strong/weak evolution in galaxy surface brightness is entirely due to a strong/weak luminosity evolution since z=1. This study thus rules ...
Galaxy Formation, Reionization, the First Stars and Quasars
... UV through X-ray spectra generally have properties indistinguishable across cosmic time — most distant quasars establish their main emission characteristics by the time Universe only 7% of current age However, recent detection of high-z quasars with no emission from hot dust (likely associated with ...
... UV through X-ray spectra generally have properties indistinguishable across cosmic time — most distant quasars establish their main emission characteristics by the time Universe only 7% of current age However, recent detection of high-z quasars with no emission from hot dust (likely associated with ...
The Milky Way`s Collision with the Andromeda Galaxy
... Great Square of Pegasus, in the neighboring constellation of Andromeda, the Princess. The object has piqued the interest of astronomers for centuries. In approximately 964 AD, the Persian astronomer Abd al-Rahman al-Sufi first cataloged it in his Book of Fixed Stars as a “small cloud.” In 1764, Char ...
... Great Square of Pegasus, in the neighboring constellation of Andromeda, the Princess. The object has piqued the interest of astronomers for centuries. In approximately 964 AD, the Persian astronomer Abd al-Rahman al-Sufi first cataloged it in his Book of Fixed Stars as a “small cloud.” In 1764, Char ...
Distance Determination of the Hubble Constant Ho by the
... • She studied 25 Cepheids in the Small Megallanic Cloud and assuming that all the stars where about the same distance away, found that the brighter stars had longer periods. • In 1924 Edwin Hubble used this relation to measure the distance to a number of other galaxies and discovered that the univer ...
... • She studied 25 Cepheids in the Small Megallanic Cloud and assuming that all the stars where about the same distance away, found that the brighter stars had longer periods. • In 1924 Edwin Hubble used this relation to measure the distance to a number of other galaxies and discovered that the univer ...
*Death of the Sun* * Video Questions
... 3. What did Eric Becklin and his team of astronomers use to pinpoint the center of the Milky Way Galaxy? What did it allow them to do? 4. How many light years across is the Milky Way Galaxy? 5. What lies at the center of our Milky Way Galaxy? 6. What do massive objects like the Sun do to the fabric ...
... 3. What did Eric Becklin and his team of astronomers use to pinpoint the center of the Milky Way Galaxy? What did it allow them to do? 4. How many light years across is the Milky Way Galaxy? 5. What lies at the center of our Milky Way Galaxy? 6. What do massive objects like the Sun do to the fabric ...
Hubble`s Law Lab - The University of Texas at Austin
... recessional velocity of a hypothetical galaxy that is exactly following Hubble’s law. The distance associated with it is how far that galaxy has separated from us during the age of the Universe, and the velocity is the rate at which it is separating from us. We can therefore use the same formula for ...
... recessional velocity of a hypothetical galaxy that is exactly following Hubble’s law. The distance associated with it is how far that galaxy has separated from us during the age of the Universe, and the velocity is the rate at which it is separating from us. We can therefore use the same formula for ...
The Mystery of the Giant Galactic Blobs
... Twelve hours of IRAC imaging have been approved and still await scheduling. This will allow measurement of stellar mass. Deep CTIO 4m near-infrared JHK imaging is scheduled for July. This will provide a crucial measurement of the SEDs around the 4000Å break of objects at z=2.38, allowing identificat ...
... Twelve hours of IRAC imaging have been approved and still await scheduling. This will allow measurement of stellar mass. Deep CTIO 4m near-infrared JHK imaging is scheduled for July. This will provide a crucial measurement of the SEDs around the 4000Å break of objects at z=2.38, allowing identificat ...
Dark Matter: Observational Constraints
... Does Dark Matter Exist? • Velocity Dispersion of Galaxies in Clusters (Virial Theorem) • Zwicky (1933, 1937) – Used term “dark matter” perhaps for first time – Suggested using gravitational lensing to measure galaxy masses – Suggested using virial theorem to measure masses of galaxy clusters – But ...
... Does Dark Matter Exist? • Velocity Dispersion of Galaxies in Clusters (Virial Theorem) • Zwicky (1933, 1937) – Used term “dark matter” perhaps for first time – Suggested using gravitational lensing to measure galaxy masses – Suggested using virial theorem to measure masses of galaxy clusters – But ...
AST 346, Galaxies, Part 6
... older than the disk. Alternatively, they could have formed later as gas spirals to center. Some z > 3 galaxies are apparently building bulges, but a rare case, NGC 7331, has some bulge stars orbiting opposite to the bulge itself, J.M. Lattimer ...
... older than the disk. Alternatively, they could have formed later as gas spirals to center. Some z > 3 galaxies are apparently building bulges, but a rare case, NGC 7331, has some bulge stars orbiting opposite to the bulge itself, J.M. Lattimer ...
Expansion of the Universe
... us. The velocity of the moving body is measured using the Doppler Effect or spectral line shift. The distance is more difficult to measure. It is measured by its apparent angular size or brightness of objects. Using observable evidence Hubble Law tells us that our Universe is expanding. We observe g ...
... us. The velocity of the moving body is measured using the Doppler Effect or spectral line shift. The distance is more difficult to measure. It is measured by its apparent angular size or brightness of objects. Using observable evidence Hubble Law tells us that our Universe is expanding. We observe g ...
Statistical challenges in modern astronomy
... modeled as the observed values of random variables, to provide a framework from which inductive conclusions may be drawn about the mechanism giving rise to the data." (Univ Cambridge text, 2005) 7. "The goal of science is to unlock nature's secrets. ... Our understanding comes through the developmen ...
... modeled as the observed values of random variables, to provide a framework from which inductive conclusions may be drawn about the mechanism giving rise to the data." (Univ Cambridge text, 2005) 7. "The goal of science is to unlock nature's secrets. ... Our understanding comes through the developmen ...
Seyfert galaxy
Seyfert galaxies are one of the two largest groups of active galaxies, along with quasars. They have quasar-like nuclei (very luminous, distant and bright sources of electromagnetic radiation) with very high surface brightnesses whose spectra reveal strong, high-ionisation emission lines, but unlike quasars, their host galaxies are clearly detectable.Seyfert galaxies account for about 10% of all galaxies and are some of the most intensely studied objects in astronomy, as they are thought to be powered by the same phenomena that occur in quasars, although they are closer and less luminous than quasars. These galaxies have supermassive black holes at their centers which are surrounded by accretion discs of in-falling material. The accretion discs are believed to be the source of the observed ultraviolet radiation. Ultraviolet emission and absorption lines provide the best diagnostics for the composition of the surrounding material.Seen in visible light, most Seyfert galaxies look like normal spiral galaxies, but when studied under other wavelengths, it becomes clear that the luminosity of their cores is of comparable intensity to the luminosity of whole galaxies the size of the Milky Way.Seyfert galaxies are named after Carl Seyfert, who first described this class in 1943.