; file: exthminbf_wsa.pro ; init: Oct 9 2013 Rob Rutten ; last: Oct 9 2013 Rob Rutten ; note: from otherdirs/asensio/kh_bf.pro function exthminbf_wsa,temp,elpress,wav ; PURPOSE: ; compute negative hydrogen bound-free continuum extinction ; per H atom (cm**2), according to ; John, 1989, A&A 193, 189 (he has a couple of mistakes) ; RJR = 1988A%26A...193..189J (Jorge's year is also a mistake) ; ; INPUT: ; temp temperature (k) ; elpress electron pressure ; wav wavelength in AA larger than 1250 AA ; ; output: ; H_min bound-free continuous extinction coefficient ; ; MODIFICATION HISTORY: ; finished:20/2/90)for SOS ; Sept 1st, 95fortran > idl (jorge) ; Oct 9 2013: RJR cosmetics ; definitions & constants lambda_0=1.6419d0 alfa=1.439d4 const=.75d-18 cc=[152.519d0,49.534d0,-118.858d0,92.536d0,-34.194d0,4.982d0] ; kh_bf t=temp pe=elpress lambda=wav/1.e4 if(lambda lt lambda_0)then begin com=1./lambda-1./lambda_0 e=findgen(6)/2. ; idl style sigma=total(cc*com^e) ; idl style sigma=lambda^3.*com^1.5*sigma kh_bf=t^(-2.5)*exp((alfa/lambda_0)/t)*(1.-exp(-(alfa/lambda)/t)) kh_bf=(const*sigma)*kh_bf endif else begin kh_bf=0.d0*t endelse ; return kh_bf=kh_bf*pe return,float(kh_bf) end