Where is DP0.2 the Dustiest?

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#1

I’m comparing fluxes with their de-reddened values in a 1º radius patch of DP0.2 sky at 62º, -37º and not getting much of a difference. Does anyone know where the DP0.2 sky is dustiest? Thanks : )

#2

I believe that the region around 62, -37 is not very dusty at all. One way to check this is to determine the total column density of intervening gas - and it is always less than 10^20 equivalent hydrogen atoms per cm^2, this location is, if I recall correctly ~ 45 degrees South of the Galactic plane. To the first order, the dustiest region would be closest to the Galactic plane. I hope this helps! If you want to get a 3D distribution of dust - I think Greg Green published such maps for the Galaxy, will find the reference if you need it.

#3

Converting from celestial to Galactic coordinates reveals that the region around the the RA = 70 deg, dec = -27.5 deg corner of DC2 footprint is the closest to the Galactic plane, at the Galactic latitude of ~ -39 degrees, and thus it is expected to have the highest hydrogen column density and thus the highest extinction. Extinction is linearly related to the hydrogen column density N_H (see Guver and Ozel 2009, MNRAS 400, p. 2050 where they report the measured relationship between A_v and N_H to be N_H ~ 2x10^21 x A_v). Specifically the hydrogen column density (from the colden tool at HEASARC) in that region is highest, ~ 2.8 x 10^20 cm^-2 . This corresponds to A_v of ~ 0.14.

Melissa also pointed out that IPAC provides a webtool which is probably more useful for this situation: Galactic DUST Reddening & Extinction . Also note that the Section 5.3 of the DESC’s DC2 paper cites exactly the Galactic dust model used for Milky Way sources at the end of the first paragraph.

BTW, independently, I checked and the maps made by Greg Green do not reach the DC2 footprint, so please ignore that comment in my original reply.

#4

Thank you for this, Greg! That’s very helpful.

#5

Hi Bob – Thanks for the interesting question! I’m going to mark Greg’s second reply as the solution, but let me know if you disagree. Thanks again…