TYPE II SUPERNOVAE AS DISTANCE INDICATORS by Mario
... A significant fraction of the data included in this dissertation comes from unpublished observations obtained by several colleagues. I thank them for their great generosity, a rare virtue in the competitive world of modern astronomy. In particular, I would like to acknowledge the help and collaborat ...
... A significant fraction of the data included in this dissertation comes from unpublished observations obtained by several colleagues. I thank them for their great generosity, a rare virtue in the competitive world of modern astronomy. In particular, I would like to acknowledge the help and collaborat ...
this article
... formation rates. While the majority of Sa–Sab galaxies in our sample are forming stars at a modest rate, a significant fraction (29%) exhibit star formation rates greater than 1 M yr1, rivaling the most prolifically star-forming latetype spirals. A similar diversity is apparent in the star format ...
... formation rates. While the majority of Sa–Sab galaxies in our sample are forming stars at a modest rate, a significant fraction (29%) exhibit star formation rates greater than 1 M yr1, rivaling the most prolifically star-forming latetype spirals. A similar diversity is apparent in the star format ...
H-alpha Imaging of Early-type (Sa
... selected by Kennicutt (1983) and Kennicutt (1994) is small in number and is biased towards galaxies with low values of L(FIR)/L(B) (Devereux & Hameed 1997; Usui et al. 1998). We are, therefore, conducting an Hα imaging survey of all known nearby early-type spiral galaxies in order to better understa ...
... selected by Kennicutt (1983) and Kennicutt (1994) is small in number and is biased towards galaxies with low values of L(FIR)/L(B) (Devereux & Hameed 1997; Usui et al. 1998). We are, therefore, conducting an Hα imaging survey of all known nearby early-type spiral galaxies in order to better understa ...
Galaxy And Mass Assembly (GAMA): Gas Fuelling of Spiral Galaxies
... We quantify the effect of the galaxy group environment (for group masses of 1012.5 to 1014.0 M ) on the current star formation rate (SFR) of a pure, morphologically-selected, sample of disk-dominated (i.e. late-type spiral) galaxies with redshift ≤ 0.13. The sample embraces a full representation of ...
... We quantify the effect of the galaxy group environment (for group masses of 1012.5 to 1014.0 M ) on the current star formation rate (SFR) of a pure, morphologically-selected, sample of disk-dominated (i.e. late-type spiral) galaxies with redshift ≤ 0.13. The sample embraces a full representation of ...
Annual Report 2012
... of our outreach activities was the extensive press coverage of the spectacular work by the Hubble Space Telescope to obtain the deepest images of the extragalactic sky. Vincent Icke presented these results on ‘De Wereld Draait Door’ daily show, while Ivo Labbé appeared on the ‘Pauw en Witteman’ the ...
... of our outreach activities was the extensive press coverage of the spectacular work by the Hubble Space Telescope to obtain the deepest images of the extragalactic sky. Vincent Icke presented these results on ‘De Wereld Draait Door’ daily show, while Ivo Labbé appeared on the ‘Pauw en Witteman’ the ...
raman scattering by molecular hydrogen and nitrogen
... The effects of Raman scattering on planetary albedos and its potential for probing planetary atmospheres has been known and studied for a few decades, mostly in the context of Solar System planets (for reviews of the early studies of Raman scattering see Price 1977; Cochran 1981). The purpose of thi ...
... The effects of Raman scattering on planetary albedos and its potential for probing planetary atmospheres has been known and studied for a few decades, mostly in the context of Solar System planets (for reviews of the early studies of Raman scattering see Price 1977; Cochran 1981). The purpose of thi ...
- Durham Research Online
... that experience such quenching in their analysis ranges from 30% to 75%, depending on the local density, but not at all on halo mass (above 1012 M ). This indicates that environmental effects may thus be relevant as galaxies enter group-sized halo potentials and there become satellites of the centr ...
... that experience such quenching in their analysis ranges from 30% to 75%, depending on the local density, but not at all on halo mass (above 1012 M ). This indicates that environmental effects may thus be relevant as galaxies enter group-sized halo potentials and there become satellites of the centr ...
Lyman-alpha imaging of starburst galaxies in the local universe and beyond Matthew Hayes
... with extinction curves showing successively more attenuation at shorter wavelengths (although some discrete features may be present). All extinction laws peak at FUV wavelengths, indicating strong biases may be introduced into quantities derived from FUV continuum or Lyα . However, the very first st ...
... with extinction curves showing successively more attenuation at shorter wavelengths (although some discrete features may be present). All extinction laws peak at FUV wavelengths, indicating strong biases may be introduced into quantities derived from FUV continuum or Lyα . However, the very first st ...
THE KINEMATICS OF ARP 295 IN Hα EMISSION
... side, and that Arp 295a is receding on its northeastern side. Thus, with respect to their mutual orbit, Arp 295b rotates retrograde and Arp 295a prograde. Stockton found maximum rotation velocities (inclination-corrected) of 300 km s−1 for Arp 295a (with a turnover at r = 40 arcsec) and 245 km s−1 f ...
... side, and that Arp 295a is receding on its northeastern side. Thus, with respect to their mutual orbit, Arp 295b rotates retrograde and Arp 295a prograde. Stockton found maximum rotation velocities (inclination-corrected) of 300 km s−1 for Arp 295a (with a turnover at r = 40 arcsec) and 245 km s−1 f ...
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 ...
![arXiv:1601.01542v1 [astro-ph.GA] 7 Jan 2016](http://s1.studyres.com/store/data/017487687_1-243c4cbda96da53325dd347b0c588a3e-300x300.png)
arXiv:1601.01542v1 [astro-ph.GA] 7 Jan 2016
... new stars. The ISM is fundamentally gaseous, and its chemical abundance can be derived by analysing spectroscopic features, that is, nebular emission lines. These emission lines are excited by photoionisation of the interstellar gas by hot and young massive stars (Aller 1984; Osterbrock 1989), which ...
... new stars. The ISM is fundamentally gaseous, and its chemical abundance can be derived by analysing spectroscopic features, that is, nebular emission lines. These emission lines are excited by photoionisation of the interstellar gas by hot and young massive stars (Aller 1984; Osterbrock 1989), which ...
Redshift
In physics, redshift happens when light or other electromagnetic radiation from an object is increased in wavelength, or shifted to the red end of the spectrum. In general, whether or not the radiation is within the visible spectrum, ""redder"" means an increase in wavelength – equivalent to a lower frequency and a lower photon energy, in accordance with, respectively, the wave and quantum theories of light.Some redshifts are an example of the Doppler effect, familiar in the change of apparent pitches of sirens and frequency of the sound waves emitted by speeding vehicles. A redshift occurs whenever a light source moves away from an observer. Another kind of redshift is cosmological redshift, which is due to the expansion of the universe, and sufficiently distant light sources (generally more than a few million light years away) show redshift corresponding to the rate of increase in their distance from Earth. Finally, gravitational redshift is a relativistic effect observed in electromagnetic radiation moving out of gravitational fields. Conversely, a decrease in wavelength is called blueshift and is generally seen when a light-emitting object moves toward an observer or when electromagnetic radiation moves into a gravitational field. However, redshift is a more common term and sometimes blueshift is referred to as negative redshift.Knowledge of redshifts and blueshifts has been applied to develop several terrestrial technologies such as Doppler radar and radar guns. Redshifts are also seen in the spectroscopic observations of astronomical objects. Its value is represented by the letter z.A special relativistic redshift formula (and its classical approximation) can be used to calculate the redshift of a nearby object when spacetime is flat. However, in many contexts, such as black holes and Big Bang cosmology, redshifts must be calculated using general relativity. Special relativistic, gravitational, and cosmological redshifts can be understood under the umbrella of frame transformation laws. There exist other physical processes that can lead to a shift in the frequency of electromagnetic radiation, including scattering and optical effects; however, the resulting changes are distinguishable from true redshift and are not generally referred to as such (see section on physical optics and radiative transfer).