Normal Galaxies Sample From

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Normal Galaxies Sample From 2dF-XMM Wide Angle
Survey
Yueheng Xu
Jonathan Tedds, Silvia Mateos, Mike Watson,
Matthew Page, Francisco Carrera, Mirko Krumpe,
Jacobo Herrero, Amalia Corral XMM-Newton SSC
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2dF-XMM Wide Angle Survey

• 10 degree2
• gt 3000 X-ray sources from 70 XMM observations
• Optical spectra from 2dF system on AAT in 27
  pointings
• gt 1000 sources spectroscopically identified

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2dF spectral identifications
NELG narrow emission line galaxies
GAL absorption line galaxies
BLAGN broad line AGN
STARs
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Sample selection

• Galaxies with
• (1) Absorption line or narrow emission line 2dF
  spectra
• i.e. GAL or NELG
• (2) X-ray flux to optical flux ratios 0.1, i.e.
  log10 (fX / fOPT) -1
• fX in 0.2-12 keV, and log10 (fX / fOPT)
  calculated as
• log10 (fX/fOPT) log10fX 5.5 R/2.5
• (3) X-ray luminosities LX 1043 erg s-1
• LX in 0.2-12 keV

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Sample selection

Sample sources
NELG
GAL
BLAGN

Star
The sample includes 72 normal galaxy candidates
with the mean z of 0.13.This makes up 40 of
the X-ray emitting galaxies (R lt 19) in the area
essentially those which would meet our
selection criteria.
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Information available

• X-ray spectra/hardness ratios, extent
• Optical image, spectra
• Other wavelengths Radio, IR

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Emission line ratio classification
Galaxies are marked based on their final
classifications, which does not include Composite
type as an independent type. AGN type includes
Seyfert and LINERs. One s errors are shown only
when the source has been definitely classified
under the line ratio diagnostic classification
schema.
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X-ray hardness ratio diagram
HR2(CR3-CR2)/(CR2CR3)HR3(CR4-CR3)/(CR3CR4) CR
2 0.5-1.0 keVCR3 1.0-2.0 keVCR4 2.0-4.5
keV Galaxies are marked based on their final
classifications.
Green grid non-thermal (power-law) model with G
0.75, 1.0, 1.5, 2.0, and 2.5 from top to
bottom, and NH 0, 11020, 11021, 51021,
11022, and 51022 cm-2 from left to right. Blue
grid thermal model (APEC) with kT 0.1, 0.25,
1.0, 1.5, 2.0, 2.5 and 3.0 keV from bottom to
top, and NH 0, 11020, 11021, 51021 cm-2 from
left to right.
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Absorbed AGN candidate. The 2dF optical spectrum
lacks strong emission lines, but the absorbed
hard XMM X-ray spectrum and relatively high X-ray
luminosity (LX 4.7 1041 erg s-1) indicate a
possible obscured AGN.
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Starburst Galaxy. The 2dF optical spectrum of
this system shows evidence of existence of strong
star-forming activity. The XMM X-ray spectrum
requires both hard and soft components, which is
consistent with the co-existence of a starburst
and an AGN found in infrared (Farrah et al.
2003).
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Gas halo. X-ray source extent and the soft XMM
spectrum suggest that this galaxy sits within a
group of galaxies (also evident in optical
image). The 0.2-12 keV luminosity derived from
the best fit model is 1.8 1041 erg s-1.
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Breakdown of source types definite tentative
fraction of the sample AGN 13 (18) 17
(24) 42 HII-region like galaxy 10 (14) 1
(1) 15 Has halo 12 (17) 4 (6) 22 Normal
galaxy 17 24 TOTAL
72
After excluding the AGN type sources from the
sample, the remaining normal or star-forming
galaxies have z 0.027-0.3, log10 (fX / fOPT)
(-3.5)-(-1), LX 1040.1-42.4 erg s-1.
Among the AGN (definite or tentative) in the
sample, there are 5 possible XBONGs, whose AGN
features are not accessible in optical spectra
but have hard X-ray hardness ratios and/or high
X-ray luminosities (LX gt 1042 erg s-1).
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AGN
Whole Sample
Normal (and unclassified!)
GAS
HII