X-RAY NATURE of the LINER nuclear sources Isabel M

1
X-RAY NATURE of the LINER nuclear sourcesIsabel
Márquez (IAA, Spain)

• Introduction
• The sample and the data
• Reduction and analysis
• X-ray data Spectral
  analysis
• Imaging
• CC
  diagrams
• OPTICAL HST imaging
• Discussion
• Conclusions

X-Ray Nature of the LINER Nuclear Sources O.
González-Martín, J. Masegosa, I. Márquez, M.A.
Guerrero et D. Dultzin-Hacyan AA, in press.
Astro-ph/0605629
2

• INTRODUCTION
• AGNs (Active Galactic Nuclei) produce high
  luminosities in very compact regions, usually
  temporaly variable (from hours to years)
• Therefore, more efficient (E/mass) than
  normal stellar processes
• Importance of low luminosity AGNs (LLAGN)
• - most of AGN population
• - eventual connection active/non-active nuclei
• Difficult detection
• - extinction
• - associated star formation in circumnuclear
  regions

3

• INTRODUCTION
• LINERs (Low Ionization Emission-line
  Regions)
• Group within LLAGNs
• Heckman 80 optical spectra dominated by low
  ionization emission lines
• OII3727/OIII5007 1
• OI6300/OIII5007 1/3
• Typically less luminous than Seyferts
  and QSOs
• Are them AGNs?
• The nuclear emission,
• is it originated in starbursts or from the
  accretion onto a black hole?

4

• 2. THE SAMPLE AND THE DATA
• Multiwavelength Catalogue of LINERs (MCL)
  (Carrillo 99)
• - 476 galaxies classified as LINERs
• - Information from radio to X-ray
• CHANDRA high resolution!
• Chandra ACIS archival data, public observations
  to Nov. 04 137 gxs
• Re-analysis op emission lines 122 LINERs (5 SB,
  6 Sy, 4 transition)
• Enough counts (at least 25 counts 0.5-10 keV) 51
  LINERs
• 
  
• 45 ACIS-S, 6 ACIS-I
• HST imaging 45/51 from different programs
• 31 F814W (F606W
  or F702W)

5
MCL empty histogram
LINERs normal spirals MB -20.0 -
1.5 R-X earlier Ss (selection bias)
Most from Ho 97 ULIRGs (N6240,
U8696, U5101) Abell 1795
Hickson 16 ltLFIRgt 1010 erg s-1
SAMPLE REPRESENTATIVE OF BRIGHT LINERS, no for
the most luminous in FIR
6

• 3. REDUCTION AND ANALYSIS
• 3.1 X-RAY DATA

SPECTRAL FITTING 0.5 10 keV with XSPEC
v.11.3.2 binned for 20 counts/bin before
background subtraction (CRPPHA)
23 objects SF subsample (spectral fitting)
Two models 1. power law G
2. emission from an optically thin plasma
kT
Raymond-Smith or MEKAL
absorption (phabs) NH
Solar abundances Statistics ?2 FTEST for 2nd
component
7
3 bad fitting
N4261 too complex N2681 and N7130, Bad statistics
1 purely thermal N6482 7 only power law N3690B,
N4374, N4395,
N4410A, N4594,
N4696, N5746 15
gals combined model (FTEST)
8
NH 0.1 2.9 x 1022 cm-2 kT 0.64 - 0.17
keV G 1.89 - 0.45 L(2-10 keV) 1.4x1038
1.5x1042 erg s-1
9

• Method for estimating L(2-10 keV)
• 1.8 and
• NH 3x1020 cm-2
• (galactic absorption)
• lt factor 3

10

• X-ray data. Imaging analysis
• We define the following bands
• 0.6 0.9 keV SA
• 0.9 1.2 HA
• 1.2 1.6 SB
• 1.6 2.0 HB
• 2.0 4.5 SC
• 4.5 8.0 HC
• excluding 6-7 keV

• Morphology
• AGN candidates
• unresolved, 30/51
• (N4594)
• SB candidates
• no source 21/51
• (CGCG162-010)

11
ltL(2-10 keV)gt 1.7 - 1.5x1039 erg s-1 ltL(2-10
keV)gt 1.2 - 1.3x1040 erg s-1
12
X-ray data. color-color diagrams

• Hardness ratios
• Qi (Hi-Si)/(HiSi)
• i A, B, C
• calculated for errors in S,H lt 80
• Models with G 0.4 2.6
• KT 0.1 4.0 KeV
• NH 1-30 x 1020cm-2
• combined 50 a 1keV, 1020, 1022
• N6240 G 0.8 1.0 1.03 - 0.14
• kT 0.7 0.8 0.76 - 0.06 keV
• NH 1022 1.1 - 0.1x1022

13
N315 kT0.51 (Donato 04) jets
X N6251, IC1459 PLRS ? PLMK
14
3.2.HST imaging

• Sharp-dividing
• Classification
• Compact (C) knot in X-ray nucleus (35)
  (N4552)
• Dusty (D) central dust, no knot (8)
  (N4438)

15
4. DISCUSSION

• 59 (30/51) AGN candidates
• SB candidates no AGN or obscuration
• AGNs more luminous on average, but large common
  range
• Comparison of morphological class with Ho
  01,Satyapal04 OK
• Comparison of luminosities Ho 01, Satyapal 05
  OK
• Chandra ACIS spectra soft thermal hard power
  law
• 
  kT 0.6 -0.8 keV G 1.0 4.3, ltGgt 1.8
• 
  SB similar (Ott 05, AGN gt 1.4 Sy11.56
  (Cappi 06)
• 
  Grimmes05) Sy21.61
• Sy1 kT
  0.25 keV
• 
  Similar NH ( 1020 -1022cm-2) for Sy
• 
  Luminosities within the range for Sys
• ORIGIN of X-RAY EMISSION X? (Flohic06 19 (12)
  LINERs,idem )
• LINERs like a low luminosity version of AGN?

16
4. DISCUSSION
OPTICAL All AGN-X show compact HST nuclei (28
gxs) LINERs SB-X with HST (15 gxs) 8 D-HST (5
low NH )
7 C-HST with N4696 NH, broad Ha


N3245 2 peaks Ha, radio


N4314, N7331 radio RADIO AGN
unresolved radio core flat continuum (Nagar
05, Filho 04) 16/51 observed in radio with
useful data
13 AGN radio - 9 AGN-X
- 4 SB-X
3 with 5 resolution

N5866 AGN-radio, also in X?
3 SB radio - 2 SB-X

- 1 AGN-X N4636 UV variability 7 in
common with Maoz05, 5 variable at UV, all of
them AGN-X HMXRB?


Stellar
populations life time for HMXRBs 106 107
yr 14/51 in Cid-Fernandes 04 González Delgado
04 only N3507 27 lt 108 yr

the others, lt 3
17
4. DISCUSSION
LX/LOIII as a measure of Compton thichkness for
Sys log (LX/LOIII) lt 0 Compton thick
Maiolino98 Bassani99 Panessa
Bassani02 Cappi06 Panessa06
Greater percentage of Compton-thick objects for
SB candidates
A larger percentage of AGN
LINERs ?
(Fe line, XMM)
18
5. CONCLUSIONS

• Study of nuclear properties of a sample of
  galaxies with LINER nucleus
• Morphological classification 59 AGN-X
  candidates
• Spectral fitting thermal power law
• Overlapping luminosity ranges, AGN-X more
  luminous on average
• CC diagrams interesting for obtaining physical
  parameters without spectral fitting
• All the AGN-X LINERS are C-HST, 8/14 SB-X are
  C-HST
• Evidences at radio, UV
• Contributions from HMXRBs (stellar populations)
• Simplest hypothesis low level nuclear activity
• Compton thick objects more numerous in SB
  candidates,
• increase the number
  of AGN-LINERs?