Difference between revisions of "Making the SEDs"
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1) The Excel file above contains the SED charts for the NITARP 2010 CG4 analysis. The file originated from Luisa's data file entitled "justsos+opt2.cat.tbl" which contained the short list of YSO candidates along with their magnitudes and fluxes: | 1) The Excel file above contains the SED charts for the NITARP 2010 CG4 analysis. The file originated from Luisa's data file entitled "justsos+opt2.cat.tbl" which contained the short list of YSO candidates along with their magnitudes and fluxes: | ||
| − | '' | + | ''justysos+opt2.cat.tbl - catalog (sa101 field merged with cg4 field) of just the new and old YSO candidates, with all possible bands included, optical through MIPS. short (not too many rows), but still wide ('''many''' columns).'' |
| − | justysos+opt2.cat.tbl - catalog (sa101 field merged with cg4 field) of | ||
| − | just the new and old YSO candidates, with all possible bands included. | ||
| − | short, but still wide | ||
| − | |||
| − | |||
| − | |||
2) For those optical entries with only magnitudes, fluxes were calculated using the following formula from the units page on the wiki: | 2) For those optical entries with only magnitudes, fluxes were calculated using the following formula from the units page on the wiki: | ||
| − | + | M = 2.5 * log (Fvega/F) | |
| − | divide both sides by 2.5 | + | divide both sides by 2.5 |
| − | M/2.5 = log (Fvega/F) | + | M/2.5 = log (Fvega/F) |
| − | raise both sides to the power of 10: | + | raise both sides to the power of 10: |
| − | 10^(M/2.5) = Fvega/F | + | 10^(M/2.5) = Fvega/F |
| − | solve for F: | + | solve for F: |
| − | F = Fvega/10^(M/2.5)'' | + | F = Fvega/10^(M/2.5)'' |
3) Also, the fluxes in Janskys were converted to units of F(lambda,or wavelength) using the formula lambda*mu=speed of light: | 3) Also, the fluxes in Janskys were converted to units of F(lambda,or wavelength) using the formula lambda*mu=speed of light: | ||
| − | Flux(lambda) = Flux(mu) * c/(lambda)*(lambda) | + | Flux(lambda) = Flux(mu) * c/(lambda)*(lambda) |
4) To get energy density, the flux(lambda) was then multiplied by the wavelength. | 4) To get energy density, the flux(lambda) was then multiplied by the wavelength. | ||
Latest revision as of 19:17, 4 January 2011
File:Seds from justysos+opt2.cat 20101222.xlsx
Here's a synopsis on how the SED plots were made.
1) The Excel file above contains the SED charts for the NITARP 2010 CG4 analysis. The file originated from Luisa's data file entitled "justsos+opt2.cat.tbl" which contained the short list of YSO candidates along with their magnitudes and fluxes: justysos+opt2.cat.tbl - catalog (sa101 field merged with cg4 field) of just the new and old YSO candidates, with all possible bands included, optical through MIPS. short (not too many rows), but still wide (many columns).
2) For those optical entries with only magnitudes, fluxes were calculated using the following formula from the units page on the wiki:
M = 2.5 * log (Fvega/F) divide both sides by 2.5 M/2.5 = log (Fvega/F) raise both sides to the power of 10: 10^(M/2.5) = Fvega/F solve for F: F = Fvega/10^(M/2.5)
3) Also, the fluxes in Janskys were converted to units of F(lambda,or wavelength) using the formula lambda*mu=speed of light:
Flux(lambda) = Flux(mu) * c/(lambda)*(lambda)
4) To get energy density, the flux(lambda) was then multiplied by the wavelength.
5) Finally, the first SED was made by plotting lambda*flux vs lambda on a logarithmic scale. The rest of the SEDs were then created in separate tabs by creating copies of the first SED plot (to preserve exact plot size and formatting).
6) Formatting the data points was done simply by selecting the points, double clicking, and editing the color and shape.
7) Checks were made by comparing the final SEDs with the same set created independently by Luisa.
