Introduc on to the Fundamental Astrophysics Course
... undergoes a sequence of radical changes during its life)me. • Depending on the mass of the star, this life)me ranges from only a few million years for the most massive to trillions of years fo ...
... undergoes a sequence of radical changes during its life)me. • Depending on the mass of the star, this life)me ranges from only a few million years for the most massive to trillions of years fo ...
The 2006 RBSE Journal - National Optical Astronomy Observatory
... Significant variation was detected; and there were a couple of microvariability events in the graph. The time scale if the change is such that something exceptionally small must have interfered with the flux to cause it. With changes happening over the course of just a few minutes could be caused by ...
... Significant variation was detected; and there were a couple of microvariability events in the graph. The time scale if the change is such that something exceptionally small must have interfered with the flux to cause it. With changes happening over the course of just a few minutes could be caused by ...
White dwarfs from GAIA: The 7th dimension
... • The white dwarf luminosity function of Gaia is a sensitive probe of the averaged star formation rate • Due to their very short main-sequence lifetimes the shape of the SFR can be reconstructed from the luminosity function of massive white dwarfs • To achieve these goals, we need R~5000 spectroscop ...
... • The white dwarf luminosity function of Gaia is a sensitive probe of the averaged star formation rate • Due to their very short main-sequence lifetimes the shape of the SFR can be reconstructed from the luminosity function of massive white dwarfs • To achieve these goals, we need R~5000 spectroscop ...
13.1 Galaxy Evolution: Introduction
... to know what is the initial mass function - the distribution of stars by mass when they're formed - because stars of different masses can evolve at very different pace. Then, for each stellar mass and and age we need a spectrum. So, we need libraries of stellar spectra that can b ...
... to know what is the initial mass function - the distribution of stars by mass when they're formed - because stars of different masses can evolve at very different pace. Then, for each stellar mass and and age we need a spectrum. So, we need libraries of stellar spectra that can b ...
A Horse of a Different Color
... A bright, newborn star (enlarged above) is seen emerging from the dark cloud. The star formed from gas and dust inside the nebula. Now, the star’s light illuminates the gas from which it was born. The star’s energetic light is slowly heating and eroding more of the cold gas and dust around it. ...
... A bright, newborn star (enlarged above) is seen emerging from the dark cloud. The star formed from gas and dust inside the nebula. Now, the star’s light illuminates the gas from which it was born. The star’s energetic light is slowly heating and eroding more of the cold gas and dust around it. ...
A Direct Empirical Proof of the Existence of Dark Matter
... aperture size was chosen as smaller apertures had sig nificantly higher kappa measurement errors and larger apertures resulted in significant overlap of the apertures. Plasma masses were computed from a multicomponent 3 dimensional cluster model fit to the Chandra X-ray image (details of this fit will ...
... aperture size was chosen as smaller apertures had sig nificantly higher kappa measurement errors and larger apertures resulted in significant overlap of the apertures. Plasma masses were computed from a multicomponent 3 dimensional cluster model fit to the Chandra X-ray image (details of this fit will ...
Metallicity maps
... but ram-pressure stripping is very important), they yield different metal distributions and have different time scales ram-pressure in the outskirts of clusters is sufficient to strip gas and form new stars inhomogeneous metallicity distribution, enriched material is not mixed immediately with I ...
... but ram-pressure stripping is very important), they yield different metal distributions and have different time scales ram-pressure in the outskirts of clusters is sufficient to strip gas and form new stars inhomogeneous metallicity distribution, enriched material is not mixed immediately with I ...
Massive z~1.3 evolved galaxies revealed
... does not make sense since these ages are much larger than the Hubble time at z ∼ 1.2. By forcing galaxies to have ages lower than the Hubble time at this z the only good result is obtained with Z = 2 Z models which provide a good fit to the data in the case of a 3.5 Gyr old τ = 0.1 (P(χ̃2 ) 0.95) ...
... does not make sense since these ages are much larger than the Hubble time at z ∼ 1.2. By forcing galaxies to have ages lower than the Hubble time at this z the only good result is obtained with Z = 2 Z models which provide a good fit to the data in the case of a 3.5 Gyr old τ = 0.1 (P(χ̃2 ) 0.95) ...
Galaxies on Sub-Galactic Scales
... accumulated sufficient primordial hydrogen gas and turned it into stars like their more massive brethren they should be visible as small Milky Way satellite galaxies today. However, there were only eleven. Taking these numbers from computer simulations and observations at face value there is a diffe ...
... accumulated sufficient primordial hydrogen gas and turned it into stars like their more massive brethren they should be visible as small Milky Way satellite galaxies today. However, there were only eleven. Taking these numbers from computer simulations and observations at face value there is a diffe ...
Chemical abundances and winds of massive stars in M31: a B
... (0.06 and 0.10 respectively) reflect the reddening from intervening Galactic material. This Milky Way extinction is similar to what we expect for the OB 10-64. Using these two stars and OB 10-64 we derive a mean M31 extinction law, which confirms the lack of a 2175Å feature in M31, similar to the S ...
... (0.06 and 0.10 respectively) reflect the reddening from intervening Galactic material. This Milky Way extinction is similar to what we expect for the OB 10-64. Using these two stars and OB 10-64 we derive a mean M31 extinction law, which confirms the lack of a 2175Å feature in M31, similar to the S ...
Large-scale, Optical/Near-IR Galaxy Surveys with a 4
... too. Obvious applications besides galaxy evolution include: dark energy; the largescale structure of the universe; quasars, absorption systems, and the intergalactic medium. The important point here is that the same survey observations can be used for all these applications. Other applications besid ...
... too. Obvious applications besides galaxy evolution include: dark energy; the largescale structure of the universe; quasars, absorption systems, and the intergalactic medium. The important point here is that the same survey observations can be used for all these applications. Other applications besid ...
IDENTIFICATION OF MAIN-SEQUENCE STARS WITH MID
... some objects lack photometry at one or more of the eight bandpasses. The GSC V-band photometry was extracted from photometric plates, and most stars have V-band uncertainties of 0.4 mag (see the GSC documentation for more information). The eight photometric data points were fit with Kurucz ATLAS 9 ...
... some objects lack photometry at one or more of the eight bandpasses. The GSC V-band photometry was extracted from photometric plates, and most stars have V-band uncertainties of 0.4 mag (see the GSC documentation for more information). The eight photometric data points were fit with Kurucz ATLAS 9 ...
Astrophysical false positives in direct imaging for exoplanets: a white
... composed of 12 acquisitions on the source with small dithering and one acquisition on the sky. Immediately after observing our science targets, we observed the standard star HIP 17280 (B5V) following an AB pattern to correct our spectra for telluric features. HD 8049 and the standard were both obser ...
... composed of 12 acquisitions on the source with small dithering and one acquisition on the sky. Immediately after observing our science targets, we observed the standard star HIP 17280 (B5V) following an AB pattern to correct our spectra for telluric features. HD 8049 and the standard were both obser ...
Chemical abundances and winds of massive stars in M31: a Btype
... their M31 target stars prevented strong constraints being placed on the exact shape of this extinction curve. We have briefly reinvestigated this issue using a slightly different procedure, following Fitzpatrick (1986) in using other B-type supergiants in the LMC as the comparison stars. We chose Sk ...
... their M31 target stars prevented strong constraints being placed on the exact shape of this extinction curve. We have briefly reinvestigated this issue using a slightly different procedure, following Fitzpatrick (1986) in using other B-type supergiants in the LMC as the comparison stars. We chose Sk ...
Clusters as laboratories for the study of galaxy evolution
... merging, it took place at higher redshifts (z >> 1 ) than is predicted by current semianalytical models.” p.s. van Dokkum and Stanford, 2003 ApJ, 585, 78, have measured velocity “…bright endfor of the was already in dispersions 3 ofLF the bright galaxies in this cluster, which confirm the large mass ...
... merging, it took place at higher redshifts (z >> 1 ) than is predicted by current semianalytical models.” p.s. van Dokkum and Stanford, 2003 ApJ, 585, 78, have measured velocity “…bright endfor of the was already in dispersions 3 ofLF the bright galaxies in this cluster, which confirm the large mass ...
UvA-DARE (Digital Academic Repository)
... Figuree 1.3: Conservative evolutionary scenario for the formation of a Be/X-ray binary, out of a close pairr of early B stars with masses of 13.0 M 0 and 6.5 M 0 . The numbers indicate mass (M 0 ). After the endd of the mass transfer, the Be star presumably has a circumstellar disc or shell of matte ...
... Figuree 1.3: Conservative evolutionary scenario for the formation of a Be/X-ray binary, out of a close pairr of early B stars with masses of 13.0 M 0 and 6.5 M 0 . The numbers indicate mass (M 0 ). After the endd of the mass transfer, the Be star presumably has a circumstellar disc or shell of matte ...
PPT presentation
... Monk et al. (1988) analysed 3.9m AAT spectra of 21 SMC and 50 LMC PNe. They found that the PN and HII region abundances of oxygen and neon agreed within the same galaxy but that the PN nitrogen was enhanced by 0.9 dex in the SMC and LMC. Interpreted as due to CN cycle processing of almost all of th ...
... Monk et al. (1988) analysed 3.9m AAT spectra of 21 SMC and 50 LMC PNe. They found that the PN and HII region abundances of oxygen and neon agreed within the same galaxy but that the PN nitrogen was enhanced by 0.9 dex in the SMC and LMC. Interpreted as due to CN cycle processing of almost all of th ...
document
... Any astrometric or RV campaign to look for Earths (~1AU) will have an observing campaign lasting 5 yrs or longer. There are short (1~2) year periods during the sun spot cycle when the sun in very quiet, but a 5~15 year, astrometric or RV campaign will see the “average” sun. ...
... Any astrometric or RV campaign to look for Earths (~1AU) will have an observing campaign lasting 5 yrs or longer. There are short (1~2) year periods during the sun spot cycle when the sun in very quiet, but a 5~15 year, astrometric or RV campaign will see the “average” sun. ...
Stellar Evolution
... Observed brightness combined with large distance implies huge energy output of GRBs, if they are emitting isotropically: E ~ 1054 erg L ~ 1051 erg/s ...
... Observed brightness combined with large distance implies huge energy output of GRBs, if they are emitting isotropically: E ~ 1054 erg L ~ 1051 erg/s ...
The Milky Way and Dark Matter
... You may have heard of the mysterious term "dark matter" before. Similar to black holes, dark matter does not emit light. However, unlike black holes, dark matter does not absorb light either. Instead, dark matter lets light pass through it, so it is impossible to take pictures of it. You might wonde ...
... You may have heard of the mysterious term "dark matter" before. Similar to black holes, dark matter does not emit light. However, unlike black holes, dark matter does not absorb light either. Instead, dark matter lets light pass through it, so it is impossible to take pictures of it. You might wonde ...
11.3 MB PDF file
... our filters in a collimated beam, near the image of the entrance pupil, rather than near the focal plane of the telescope as we do for less critical applications. Furthermore, we calibrate our filters in situ: we leave them in our instrument and illuminate the entrance aperture with light from a mon ...
... our filters in a collimated beam, near the image of the entrance pupil, rather than near the focal plane of the telescope as we do for less critical applications. Furthermore, we calibrate our filters in situ: we leave them in our instrument and illuminate the entrance aperture with light from a mon ...
The Death of Massive Stars
... 10,000 km diameter (3/4 of Earth’s), and a teaspoon of white dwarf material would weigh 2 tons. • Astronomers estimate that 10% of all stars are white dwarfs. • A black dwarf is the theorized “final” state of a star with a main sequence mass less than about 8 solar masses, in which all of its energy ...
... 10,000 km diameter (3/4 of Earth’s), and a teaspoon of white dwarf material would weigh 2 tons. • Astronomers estimate that 10% of all stars are white dwarfs. • A black dwarf is the theorized “final” state of a star with a main sequence mass less than about 8 solar masses, in which all of its energy ...
galaxies2_1_complete - Astronomy & Astrophysics Group
... In any case, mass distribution of neighbouring halos may overlap: Galaxies which appear as separate luminous objects may have formed from a single dark matter halo – the result of an earlier halo merger ...
... In any case, mass distribution of neighbouring halos may overlap: Galaxies which appear as separate luminous objects may have formed from a single dark matter halo – the result of an earlier halo merger ...
Grade 8 Earth/Space Pretest
... 4. In 1995, the Hubble Space Telescope photographed a tiny spot in the sky for a period of ten days; 342 exposures were placed together to create an image known as the Hubble Deep Field. Although the sample is tiny, it is representative of the universe, which looks similar in all directions. The ima ...
... 4. In 1995, the Hubble Space Telescope photographed a tiny spot in the sky for a period of ten days; 342 exposures were placed together to create an image known as the Hubble Deep Field. Although the sample is tiny, it is representative of the universe, which looks similar in all directions. The ima ...
When Stars Attack! In Search of Killer Supernovae
... In hot core: fusion Light elements combine hydrogen ...
... In hot core: fusion Light elements combine hydrogen ...
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.