PHYSICS Part IA Wednesday 19 January 2009 SELWYN COLLEGE REVISION TEST Attempt all three questions from section A and any two from section B. SECTION A ­ answer all questions. ... 5] A2 A3 SECTION B ­ answer two questions B4. ... 5] A uniform solid cylinder rolls from rest without slipping down a rough inclined plane, then along a horizontal section where the surface texture changes from rough to smooth, and finally up a second inclined plane with a perfectly-smooth surface. ...

Q: Are the magnitudes in the ETCs AB or Vega magnitudes? ... Q: How is the signal to noise defined? A: In optical and infrared imaging, the applications display a signal to noise over the PSF area, which is computed in a circle of radius seeing/plate_scale. ... In optical imaging only, a second signal to noise is computed which is the signal to noise at the central pixel. ... A: The template spectra stored in the database are measured or simulated spectra covering different wavelength range. ...

A spherical meteorite of radius 3m enters the Earth's atmosphere at an altitude of 100km and a speed (relative to the Earth) of 30 km/s. The atmosphere slows it down, so when it hits the Earth's surface it is travelling at only 1 km/s. If half of the heat generated as it passes through the atmosphere is absorbed by the meteorite, how hot will it be when it is about to land? ... However, the number I calculated (500,000 K) is correct, as is the discussion that follows it. ...

Blackholes Forum Message . ... Good Question. ... We really don’t know what causes gravity ( mass properties ) only how it works in the present universe state. ... It may be that you have just proven your assumption is wrong and gravity/mass properties do depend on the present universe state to exist. ... www.astronomy.net . About Astronomy Net | ... Forum posts are Copyright their authors as specified in the heading above the post. "dbHTML," "AstroGuide," "ASTRONOMY.NET" & "VA.NET" . ...

SAS home . ... List of SAS threads . Let us assume we are working in /home/user/my_work and have our XMM observation data files in /home/user/sasdata/ <my_obs>, where <my_obs> identifies a specific XMM observation. ... 2) Where are stored all the Calibration files? ... That is done by creating a Calibration Index File ( CIF ) which will tell our reduction processes which CCF s we need to use out of all available in SAS_CCFPATH , for the specific date of our observation data. ...

Next: Young Energetic pulsars Up: A Tutorial on Radio Previous: The population of millisecond . Assuming a thin-screen model, calculate the apparent angular diameter of the Crab pulsar at 600 MHz. Assume that the apparent angular diameter = 100mas at 100 MHz. Calculate the apparent angular diameter at 600 MHz if the screen is located at 1% of the distance from the pulsar to the Earth. ... Calculate the parallax's for pulsars with distances of 100, 500, 1000, 5000, 10000 parsecs. ...

... By using the tools of sections (20) and (21), the mathematics of approximate solutions developed in (M-5), and assuming all orbits are circles, it is a relatively straightforward job to calculate the distance to the Lagrangian L1 point (or to L2). ... Let the gravitational constant be denoted by G , the mass of the Sun by M , that of Earth by m , the Earth's distance from the Sun by r and its velocity in its orbit by v . ... GMm / r 2 = mv 2 / r . and multiplying both sides by r / m . ...

... 22.04.2013 . ... The Big Dipper . ... This common question frequently precedes the rediscovery of one of the most commonly recognized configurations of stars on the northern sky: the Big Dipper. ... But near local midnight on April 11, this mosaic of 3 minute long exposures revealed a green, unusually intense, atmospheric airglow stretching over thin clouds. ... This skyscape finds an esthetic balance of interstellar dust and gas residing in the suburbs of the nebula rich constellation of Orion. ...

http://hea-www.harvard.edu/AstroStat/slog/2008/eotw- grating - dispersion / Weaving together Astronomy+Statistics+Computer Science+Engineering+Intrumentation, far beyond the growing borders Fri, 01 Jun 2012 18:47:52 +0000 hourly 1 http://wordpress.org/?v=3.4 http://hea-www.harvard.edu/AstroStat/slog/2008/eotw- grating - dispersion /comment-page-1/#comment-274 ... I'm still seeking answers to <b>systematic errors</b>, measurement errors, and how to model these uncertainties. ...

Europa ("yoo ROH puh") is the sixth of Jupiter 's known satellites and the fourth largest; it is the second of the Galilean moons. ... Discovered by Galileo and Marius in 1610. ... But Europa's surface is not at all like anything in the inner solar system. ... The images of Europa's surface strongly resemble images of sea ice on Earth. It is possible that beneath Europa's surface ice there is a layer of liquid water , perhaps as much as 50 km deep, kept liquid by tidally generated heat. ...

... B ut Europa's surface is not at all like anything in the inner solar system. ... T he images of Europa's surface strongly resemble images of sea ice on Earth. It is possible that beneath Europa's surface ice there is a layer of liquid water , perhaps as much as 50 km deep, kept liquid by tidally generated heat. ... It is most likely generated by sunlight and charged particles hitting Europa's icy surface producing water vapor which is subsequently split into hydrogen and oxygen. ...

... spectrum . ... SPECTRUM will compute synthetic spectra, line profiles equivalent widths, specific intensities, assuming LTE, from model atmospheres of early-type stars. ... sterne models . file containing model atmosphere in 2006 Sterne format . ... T=25000, log g=4.0, vt=0, 1400-1415A. a) NLTE model atmosphere, spectrum computed with SYNSPECv25 (black). b) LTE model atmosphere, same linelist in converted format, spectrum computed with SPECTRUM (red) using this input file and this linelist . ...

... In this talk, I will discuss a study of the effect of ionization on the low end of HI mass function. The existence of a large population of low mass galaxies follows from CDM theory. ... HIDEEP found no low HI column density galaxies. One possible explanation is that the disks are "frozen". ... We assume that galaxies are exposed to an ionizing background radiation, from a uniform quasar distribution. ... We find a gap in the average column densities around N H which drops to 10 17 cm -2 . ...

... Searching for Far Out and Wandering Worlds . ... The Real Reality Show: Would aliens be anything like us? ... The SETI Institute is after alien signals. Assuming another world is beaming a 1-million-watt radio signal in our direction, how far away can that source be before the signal is lost in intergalactic noise? ... Get instant access to subscriber content on Astronomy.com! ... If you are already registered on Astronomy.com, please log in below. ...

... Briefly, the count rate at the detector from a source at a redshift z is . ... Another possible way that could lead to arising diverse peculiarities in the - distribution induced by the sources evolution is connected with a possible non-monotonic character of the star formation rate in galaxies. ... The most prominent feature of the obtained theoretical - is a notable sharp increase at low count rates due to evolutionary effects. ...

... Hi, As I read in that introduction a network device driver has to alloc a sk_buff in it's ISR and this has to happen atomically, isn't it? ... So my idea was I alloc a few sk_buff's (with GFP_KERNEL flag) in the device drivers open function. The device driver would organize these sk_buff's as ring. Else the device driver must forbid the higher layer to free the sk_buff's. Is this possible just by setting the lock flag inside sk_buff? ... Re: Question on alloc_skb() by Erik Petersen . ...

Observatory Support . ... The science header keyword ORIENTAT is populated by adding the angle between the HST V3 axis and the detector Y axis to what we will call the "commanded roll" (North to V3 through East). The V3-detY angles that were relevant at a given observation's epoch are given as a header keyword (beta_2) in the Observation Log files (aka jitter files). ... The commanded roll and the jitter file's ROLL_AVG should agree to within 0.05 degrees, usually better than 0.02deg. ...

... We present a computer program for modelling energy flux distribution and light curves of eclipsing binaries from far ultraviolet to infrared regions. The Roche model is assumed. Proximity effects of components (reflection of radiation and surface gravity darkening) are taken into account. ... Figure 1: The surface temperature distribution for Algol A-B system before (upper plot) and after (lower plot) correction for temperature due to the irradiation effect. ...

The most up-to-date information related to atmos 3.0 are collected here due to constantly increasing interest to MASS/DIMM processing software... atmos 3.0 is still beta , so the latest version is 2.97.5 (there is also 2.98.x branch which absorbs new features) . ... M' line: . ... free seeing and its relative error . ... dimm seeing and its relative error (if dimm data are present, zeros otherwise) . ... dimm turbulence power and its relative error (if dimm data are present, zeros otherwise) . ...