# Difference between revisions of "Making the SEDs"

Line 1: | Line 1: | ||

[[File:Seds_from_justysos+opt2.cat_20101222.xlsx]] | [[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. | ||

+ | short, but still wide. all of these objects should be in the above | ||

+ | catalog, but these are just the ones identified as YSO candidates using | ||

+ | the gutermuth method, PLUS ONE MORE that Luisa has TENTATIVELY matched to a | ||

+ | previously known object without a detectable IR excess.'' | ||

+ | |||

+ | 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. |

## Revision as of 19:09, 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. short, but still wide. all of these objects should be in the above catalog, but these are just the ones identified as YSO candidates using the gutermuth method, PLUS ONE MORE that Luisa has TENTATIVELY matched to a previously known object without a detectable IR excess.

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.