README
Status of the XXL DB (December 2012)
The 100 brightest C1
With the goal of publishing the 100 brightest XXL C1 clusters in 2013,
we have performed the following operations:
- For both areas, we selected the 70 brightest clusters
(total count-rate) irrespective of the C1/C2 classification.
- We assigned them a "quality"
flag = 5. This enables a quick retrieving via the selection
formulary page.
- The 140 Q = 5
clusters constitute the preliminary working sample: 2013-CS . It
will be cleaned up as soon as deeper XMM observations and better flux
measurements are available.
- Currently 2013-CS contains:
- mostly C1 and some C2 clusters,
- a majority of new clusters and 27 clusters already published
for the LSS field.
Follow the characterisation of the 2013-CS on the XXL
wiki dedicated page.
Energy Conversion Factors
We provide below ECFs to convert the measured count-rates into fluxes
for the [0.5-2] keV band.
Warning: given the mild ECF
dependence on cluster spectrum or redshift, these values are
sufficient for the purpose of proposal
writing but
not for scientific
publications.
Proposed mean conversion factors
(F. Pacaud - January 2013)
Assuming z=0.3, T=2 keV, Abundances =0.3 (APEC model)
- LSS [Nh=2.3 E+20]
0.002015 MOS c/s ==> 1e-14
erg/cm2/s and 0.007031 PN c/s ==> 1e-14
erg/cm2/s
- BCS [Nh=1.25 E+20]
0.002008 MOS c/s ==> 1e-14
erg/cm2/s and 0.007045 PN c/s ==> 1e-14
erg/cm2/s
NB the count-rate is for MOS1.
Hence, as a rule of thumb:
a total
count-rate of ~ 0.01 c/s in the
[0.5-2] keV band corresponds to a flux of ~ 1e-14 erg/s/cm2 in the
same band; that is ~ 100 photons for 10 ks.
Contact
Contact for the XXL DB (all matters):
Elias.Koulouridis at cea.fr
Note
Before retrieving a cluster sample, please read:
README archive
August 2011