In two previous papers we investigated in detail the formation of Hydrogen lines in high pressure dMe stellar chromospheres, constraining the possible structures over a two orders of magnitude pressure range. ... We found that when decreasing the transitoin region presure (i.e. the chromospheric temperature gradient), the Balmer lines change rapidly from emission to strong absorption, then the profiles weaken and become narrower until they disappear totally (zero H$_{\alpha}$ stars). ...

Next: Infrared Data Up: Contents Previous: Optical Photometry . ... For example, one method is to derive the spectral energy distribution (SED) for a target star and compare it to the SED of a dereddened standard star. ... Temperature can be determine via the B - V color (Gilliland 1985): . ... The results produced small extinctions to the background stars of between A and A . ... The most accurate extinction calculation requires both IR and spectral data. Infrared Data . Spectroscopic Data . ...

home education > activities . ... Quick math activity that asks students to calculate scale models of a binary star system with a black hole in it. [h] . ... Students use a radiometer and a light bulb with a dimmer switch to make connections between the temperature, color, and radiation output of a star. ... This demonstration, similar to the above, from the Exploratorium Snack-book of science activities, lets students demonstrate how molecules scatter light and change the colors of the beam. [m,h] . ...

... 172 ] Briefly, the count rate at the detector from a source at a redshift z is . ... Figure 55 shows the ``Green functions'' for the double compact binary merging rate   evolution assuming no collapse anisotropy. ... Another way that diverse peculiarities in the - distribution induced by the sources evolution could arise is connected with a possible non-monotonic character of the star formation rate in galaxies. ... 22 ] Figure  56 shows two-dimensional cuts through the parameter space. ...

Context. Thermal emission by stochastically heated dust grains (SHGs) plays an important role in the radiative transfer (RT) problem for a dusty medium. ... Aims: We define an appropriate problem for benchmarking dust emissivity calculations in the context of RT simulations, specifically including the emission from SHGs. ... It also includes a series of analytically defined radiation fields to which the dust population is to be exposed and instructions for the desired output. ...

... The hotter the gas, the faster they move, and the more energy each of them holds. The free ions and electrons in a plasma behave the same way. Knowing the temperature of the high atmosphere of Earth, or that of the Sun, we can calculate energies expected of ions and electrons found there. However, ions and electrons actually observed in space are often much , much more energetic, and may move at a respectable fraction of the velocity of light (300,000 km/sec or 186,000 miles/sec). ...

... The BM effect causes low-luminosity blazars (particularly BL Lacs) to be missed in surveys because the apparent luminosity of the non-thermal nuclear source does not exceed that of the host galaxy by a large factor. ... Browne (1995). ... In addition to these objects, a large fraction of the newly-identified BL Lacs in our sample (10 of 22; see Table 5) have been so classified only by virtue of our usage of the expanded March? et al. (1996) definition of the BL Lac class. ... 1996). ...

Spectropolarimetry and modeling of Galactic Wolf-Rayet star WR156 O LGA M A RY E VA Special Astrophysical Observatory RAS; olga.maryeva@gmail.com For the first time spectropolarimetric observations of Wolf-Rayet star WR156 (WN8h sub-class) were conducted. ... This polarization is, most probably, has an interstellar origin, as its magnitude and orientation are similar to the ones of field stars. ... By its parameters WR156 is similar to other WN8h stars, displaying the line effect. ...

... ATNF Home . About ATNF . ... About ATNF overview . ... Australia Telescope Steering Committee . ... Australia Telescope User Committee . ... Astrophysics graduate student programs . ... Australian Square Kilometre Array Pathfinder . Murchison Radio-astronomy Observatory . ... Parkes radio telescope . Australia Telescope Compact Array . Mopra radio telescope . ... Visiting Parkes radio telescope . Visiting Australia Telescope Compact Array . ... Parkes radio telescope webcam . ...

... Fitting the observed dependence includes calculations of the polarization cross-sections averaged over particles orientation and size distribution, their normalization and the comparison of obtained dependencies with Serkowski's curve representing observational data for a chosen star. ... Variations of the polarization factors with wavelength are shown in Fig. 16 for homogeneous spheroidal particles with PF orientation. ... The distinction between prolate and oblate spheroids is also clearly seen. ...

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... Minute Values of Geomagnetic Field Components . ... AA 1868 - Present (3 hourly and daily) (monthly) (yearly) (Lists and histograms of geomagnetic disturbance and Solar Sunspots) KP_AP 1932 - Present (3 hourly and daily) (Lists and histograms of geomagnetic disturbance and Solar Sunspots) AE_HV 1957-75, 78-88 (hourly) AE_MIN 1978-881-6;198903;1990-94 (minute) DST 1957 - Present (hourly) PC 1975 - Present (15-minute) AMANAS 1959 - Present (3 hourly and daily) KMKNKS 1983 - Present (3 hourly) . ...

Planetary Illumination, and Its effect on Climate Models of Earth-like Exomoons Duncan Forgan1,2 , Vergil Yotov1 1 2 SUPA, Institute for Astronomy ... Compared to an Earth-like planet, there are several extra sources and sinks of energy available to an Earth-like exomoon, including: Tidal Heating Planetary Illumination (thermal flux and reflected starlight) Eclipses of the star by the planet (acts as a sink) Circumstellar HZ - Zero Moon ...

The hotbed effect (hothouse effect) in the planets atmosphere is the inside atmosphere layers heating (of the Earth, Venus etc.), due to the transparent planet atmosphere for the main part of solar radiation (in optical range). In the atmosphere of the Earth this radiation is absorbed by the molecules of H2O, C02, O3 and others. ... As a result of human activities the CO2 content is increasing (and the other gases, absorbing in infrared range). ...

... Mass . 17a. Measuring Mass . ... A medium-size (1.25 inch wide) binder clip, as is used in offices to hold papers together--the type made of flat blue steel, with two wire handles. ... The theory predicts that the oscillation period should be proportional to the square root of the oscillating mass, including the mass of the clip. Note that gravity plays no part here: the oscillation period would be the same on the Moon or in zero-g. Denoting square root by SQRT, we have . ...

... HI mass fractions Comparison samples HeViCS bright galaxy Catalogue(BGC) Davies+2012 Average scaling relations for HI-normal and extremely HI-deficient galaxies in H3 survey (Gavazzii+ 2013 ) Dwarf galaxy survey (DGS) Madden+ 2013 KINGFISH Kennicutt 2011 Specific star formation rates Schiminovich +2007 Comparison samples HeViCS bright galaxy Catalogue(BGC) Davies+2012 Dwarf galaxy survey (DGS) Madden+ 2013 KINGFISH Kennicutt 2011 Dust ...

Problem Set 2 - Cosmology­A3002 ­Due on or before November 7th. Can be sent via internal mail (Brian Schmidt, RSAA) use H0=70 km/s/Mpc, M=0.27, =0.73, w=-1 for all problems. ... Finish off your Monte Carlo simulation by selecting objects at random redshifts from 0<z<0.1, assuming that they have a mean absolute magnitude of M=-19.5 with a dispersion 0.2 magnitudes. ... Problem 2.1 (2 pt): In class we described the scale at which material can collapse in the Universe as the Jeans' length. ...

NATIONAL ASTRONOMY AND IONOSPHERE CENTER . ... Kick-Off Ceremony of the Arecibo Observatory 50th Anniversary . ... Project Supervisors: Dr. R. Minchin & Dr. R. Taylor, Arecibo Observatory . Abstract . ... Project Supervisors: Dr. R. Taylor & Dr. R. Minchin, Arecibo Observatory . ... Project Supervisors: Christiano Garnett Marques Brum, Edvier Cabassa-Miranda & Nestor Aponte, Arecibo Observatory . ... For this, we are using TEC data registered at the Arecibo Observatory site from 2004 to 2012. ...

. You can compare any two versions of a file that is under the control of SCCS with the sccsdiff command: /usr/sccs/sccsdiff -r version -r version s. filename . Using this command produces a line by line difference between the two versions of the file. Results are shown in the same format as that produced by the diff command. Examples .