Viewing RGS/50077
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Date: Wed, 02 May 2012 21:02:55 -0400
Subject: Broadening due to spatial extent of the source
From: shokoofeh nourbakhsh <snourbak@uwo.ca>
To: Jan-Uwe Ness <xmmhelp@sciops.esa.int>

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Dear Sir/Madam

I am working to RGS spectrum and I want to measure line width. I know there
is a broadening due to extent of the source which follows
delta lambda = 0.124/m delta theta
I can not figure it out that what delta lambda is? is it FWHM? is it
standard deviation? Correspond to each one half energy width of the source
in arcmin, FWHM of lambda changes or standard deviation?

Thanks for your consideration
Shokoofeh

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Dear Sir/Madam<div><br></div><div>I am working to RGS
spectrum and I want t=
o measure line width. I know there is a broadening due to extent of the sou=
rce which follows=A0</div><div>delta lambda =3D 0.124/m delta
theta=A0</div=
><div>
I can not figure it out that what delta lambda is? is it FWHM? is it standa=
rd deviation? Correspond to each one half energy width of the source in arc=
min, FWHM of lambda changes or standard
deviation?</div><div><br></div>
<div>Thanks for your
consideration</div><div>Shokoofeh</div>

--Boundary_(ID_iL5QDbmKfoHkVYGzVrNykQ)--

Reply 1

From: Ignacio de la Calle <xmmhelp@sciops.esa.int>
To: snourbak@uwo.ca
Subject: Re: Broadening due to spatial extent of the source (PR#50077)
Date: Thu May  3 15:53:49 2012

Dear Shokoofeh,

According to the Users Handbook,

http://xmm.esac.esa.int/external/xmm_user_support/documentation/uhb/rgsspecres.html

the RGS spectral resolution depends on the angular extent of the observed
source. For extended sources, emission lines are broadened according to the
relation

    Delta_lambda(ext) = 0.138 theta(ext)/m      

where Delta_lambda(ext) is the resolution in . in case of an extended source,
for the spectral order m and a source extent of theta(ext), in arcmin.

Delta_lambda(ext) is the FWHM.

Regards,

Ignacio de la Calle
XMM-Newton SOC
 
> --Boundary_(ID_iL5QDbmKfoHkVYGzVrNykQ)
> Content-type: text/plain; CHARSET=US-ASCII
> Content-transfer-encoding: 7BIT
> 
> Dear Sir/Madam
> 
> I am working to RGS spectrum and I want to measure line width. I know
there
> is a broadening due to extent of the source which follows
> delta lambda = 0.124/m delta theta
> I can not figure it out that what delta lambda is? is it FWHM? is it
> standard deviation? Correspond to each one half energy width of the source
> in arcmin, FWHM of lambda changes or standard deviation?
> 
> Thanks for your consideration
> Shokoofeh
> 
> --Boundary_(ID_iL5QDbmKfoHkVYGzVrNykQ)
> Content-type: text/html; charset=ISO-8859-1
> Content-transfer-encoding: quoted-printable
> 
> Dear Sir/Madam<div><br></div><div>I am working to
RGS spectrum and I want t=
> o measure line width. I know there is a broadening due to extent of the
sou=
> rce which follows=A0</div><div>delta lambda =3D 0.124/m delta
theta=A0</div=
>><div>
> I can not figure it out that what delta lambda is? is it FWHM? is it
standa=
> rd deviation? Correspond to each one half energy width of the source in
arc=
> min, FWHM of lambda changes or standard
deviation?</div><div><br></div>
> <div>Thanks for your
consideration</div><div>Shokoofeh</div>
> 
> --Boundary_(ID_iL5QDbmKfoHkVYGzVrNykQ)--
> 
>