Recent content by AdrianD

Let's say I have a galaxy SED like this: from synphot import SourceSpectrum from synphot.models import BlackBodyNorm1D sp = SourceSpectrum(BlackBodyNorm1D, temperature=6170.4796) wave = sp.waveset flux = sp(wave) #Photlam flux_flam = flux.to(u.erg / u.s /...

The bandwidth of the H-alpha filter is 30 A or 3 nm. I need the wavelength dependent quantity because I will compute the counts (electrons/sec) from the object. The general formula being: Flux/PhotonEnergy(λ) * Filter_bandwidth (nm) * Aperture (m^2) * QE * PlateScale^2(arcsec^2). For broadband...

I think I made some progress. The article for the Vizier data base is here: https://academic.oup.com/mnras/article/431/1/2/1036908 On pg. 12 in the pdf " with the exception of McCullough et al. (2001) who determined a flux for Abell 36 of F(Hα) = 2.8 × 10−11 erg cm−2 s−1, which is 28 per cent...

Ok, but there must be a way, otherwise there is no point to measure/report the value in the catalog if it's useless for computing flux or flux density

I have a vizier catalog with H-alpha fluxes as logF(Haplha) in units as mW/m^2. See sample data here: http://vizier.cds.unistra.fr/viz-bin/VizieR-3?-source=J/MNRAS/431/2/fluxes How do I convert mW/m^2 to W/m^2/nm or erg/s/cm^2/A? The first entry is logF(Halpha) = -12.03 mW/m^2

Signal - help I did found a help file for an older calculator. So, for extended objects the electron counts are multiplied by the area of a pixel in arc seconds. For this we use the plate scale, that determines the size of the pixel in arc seconds. If my plate scale is 0.5 arc seconds per pixel...

I am trying to compute the exposure time needed for an extended object (galaxy), in python. I have found the following formulas: Exposure time app # press the help button at the bottom of the calculator for the formulas used Exposure time calc Let's take for example the M33 galaxy. It has...