General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies
description
Transcript of General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies
![Page 1: General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies](https://reader033.fdocuments.us/reader033/viewer/2022052702/56814406550346895db09a5f/html5/thumbnails/1.jpg)
General Assembly of IAU, Symposium #238
Black Holes: From Stars to GalaxiesAug 22, 2006, Prague, Czech Republic
Presented by: George Chartas (Penn State)In collaboration with: Cristian Saez(Penn State), Xinyu Dai(OSU), Michael Eracleous(Penn State),
Niel Brandt(Penn State), Bret Lehmer(Penn State), Franz Bauer(Columbia), Gordon Garmire (Penn State)
X-ray Spectral Evolution of AGN
![Page 2: General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies](https://reader033.fdocuments.us/reader033/viewer/2022052702/56814406550346895db09a5f/html5/thumbnails/2.jpg)
Evolution of AGN
• Commonly used methods of studying the evolution of AGN include :
(a) Determining the evolution of the optical and X-ray luminosity functions and optical and X-ray space densities of AGN.
(b) Determining the evolution of the host galaxies.
(c) Determining the evolution of the spectra of the AGN ( vs z,ox vs z).
![Page 3: General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies](https://reader033.fdocuments.us/reader033/viewer/2022052702/56814406550346895db09a5f/html5/thumbnails/3.jpg)
Evolution of Space Density of type-I AGN
The space density of type-I AGN changes significantly with redshift and luminosity.
The redshift at which the space density peaks changes with luminosity from z ~ 0.5-0.7 for logLx = 42-43 ergs s-1 to z ~ 2 for logLx = 45-46 ergs s-1.
The amount of change in the space density is also strongly dependent on luminosity. ~ 10 for logLx = 42-43 ergs s-1 ~ 100 for logLx = 45-46 ergs s-1
The space density of low luminosity AGN is found to decline at high redshift.
Hasinger et al (2005)
![Page 4: General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies](https://reader033.fdocuments.us/reader033/viewer/2022052702/56814406550346895db09a5f/html5/thumbnails/4.jpg)
Evolution of Host Galaxy
Barger et al. 2005
The absolute rest-frame 5000 A luminosities of the host galaxies vs. redshift for sources inthe ACS GOODS-North region of the CDF-N. Triangles : LX > 1044 ergs s-1
Diamonds: LX = 1043 - 1044 ergs s-1
Squares: LX = 1042 - 1043 ergs s-1
![Page 5: General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies](https://reader033.fdocuments.us/reader033/viewer/2022052702/56814406550346895db09a5f/html5/thumbnails/5.jpg)
Evolution of Quasars
• One might expect to detect a change in the X-ray emission and accretion properties of quasars to accompany the dramatic change in the number density of quasars between z=1 and z=2 (Fan et al. 2001).
• Many X-ray surveys have attempted to find such a change by constraining and the optical-to-X-ray spectral index, ox
• The evolution of with z is still debatable (eg., Bechtold et al. 2003, Vignali et al. 2003, Grupe et al. 2005)
• There is no indication that correlates with luminosity for low z quasars (George et al. 2000, Reeves & Turner 2000)
Evolution of quasar comoving number density as a function of z (Fan et al. 2001)
![Page 6: General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies](https://reader033.fdocuments.us/reader033/viewer/2022052702/56814406550346895db09a5f/html5/thumbnails/6.jpg)
ox dependence on the 2500 A monochromatic luminosity.
The main sample is given by filled circles, the high-z sample by open squares, and the Sy 1 sample by open Triangles. Strateva et al. (2005)
Correlation of ox with z, only 1 sigma significant if the lUV dependence is taken into account. Strateva et al. (2005)
Dependence of aox of AGN with UV luminosity and z
![Page 7: General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies](https://reader033.fdocuments.us/reader033/viewer/2022052702/56814406550346895db09a5f/html5/thumbnails/7.jpg)
X-ray Spectra of Radio-Quiet Quasars at z > 4
Shemmer et al. (2005) performed an investigation of moderate-to-high quality X-ray spectra of 10 quasars (z = 4 - 6.28).
• They do not find any significant difference between the spectra of these high z quasars compared to ones at lower z.
• If quasars have been evolving constantly over time observations of the most distant ones may provided the most ``leverage'' for constraining any changes in the X-ray spectra over cosmic time.
= 1.97 +/- 0.05, NH < 3 X 1021 cm-2 (mean values)Fe Kα EW < 190 eV and R < 1.2
χ2 contours from joint fit forentire and common energy ranges
![Page 8: General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies](https://reader033.fdocuments.us/reader033/viewer/2022052702/56814406550346895db09a5f/html5/thumbnails/8.jpg)
X-ray Spectra of Radio-Quiet Quasars at z > 4
Shemmer et al. (2005) find significant scatter of but no systematic trend of with absolute B magnitude and redshift.
|d/dz| < 0.04
![Page 9: General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies](https://reader033.fdocuments.us/reader033/viewer/2022052702/56814406550346895db09a5f/html5/thumbnails/9.jpg)
• Employing the lensing magnification effect to observe high redshift quasars allows us to probe the luminosity range of 1043-45 ergs s-1. (This luminosity range is practically inaccessible by most Chandra observations of unlensed quasars of similarly high redshift.)
• The lensing magnification (from a few to ~ 100) allows us to obtain moderate to high S/N spectra
• The main scientific goal of our survey of quasars was to study the evolution of spectroscopic properties of high redshift RQQs by searching for a possible correlation between photon index and luminosity for high redshift quasars
Gravitational lensing as a tool to study AGN evolution
![Page 10: General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies](https://reader033.fdocuments.us/reader033/viewer/2022052702/56814406550346895db09a5f/html5/thumbnails/10.jpg)
Evolution of Radio Quiet AGN
- LX diagram from our recent analyses of high redshift (z > 1.5) radio quiet AGN. Significant correlations are found between and the 0.2-2keV (2-10keV) luminosities. The correlations are significant at the 99.9997% (98.6%) confidence levels, respectively. (Dai, Chartas, Eracleous & Garmire 2004)
![Page 11: General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies](https://reader033.fdocuments.us/reader033/viewer/2022052702/56814406550346895db09a5f/html5/thumbnails/11.jpg)
Evolution of Radio Quiet Quasars
• Photon index vs. 2-10 keV luminosity for low redshift (z < 0.1 mostly) AGN. No significant correlation is found (George et al. 2000)
![Page 12: General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies](https://reader033.fdocuments.us/reader033/viewer/2022052702/56814406550346895db09a5f/html5/thumbnails/12.jpg)
Evolution of Radio Quiet AGN
To confirm the previously observed correlation between and luminosity we have:
• Observed additional high z lensed AGN as part of the Chandra GTO program
• Have analyzed moderate-to-high redshift radio quiet AGN observed in the deep field observations performed with Chandra
The larger sample allowed us to:
• Place tighter constraints on the correlation
• Test the correlation in narrower redshift bands and thus better constrain the epochs at which possible changes in the average emission properties of AGN occurred.
![Page 13: General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies](https://reader033.fdocuments.us/reader033/viewer/2022052702/56814406550346895db09a5f/html5/thumbnails/13.jpg)
Evolution of Radio Quiet AGN
Recent lensed high redshift AGN observed with Chandra and added to our sample
Q 0142-100
BRI 0952-0115
Q 1017-207
SBS 1520+530
SDSS 0903+5028
Object zs ms Exposure (ks)
2.72
4.50
2.55
1.59
3.605
I=16.47
I=18.3
I=16.78
I=17.61
R=19.56
15
20
15
20
20
100
90
80
70
60
50
40
30
20
10
0
X-axis (0.1 arcsec per bin)
E
N
B
A
6040302010 90807050 1000
10 15 20 25 30
30
25
20
15
10
5
0
X-axis (0.15 arcsec per bin )
E
N
B
A
50
10 15 20 25 30 35 40 45 50
50
45
40
35
30
25
20
15
10
5
0
X-axis (0.1 arcsec per bin)
E
N
X
BA
50
60
50
40
30
20
10
0
X-axis (0.125 arcsec per bin)
E
N
B
A
A
0 10 20 30 40 50 60
![Page 14: General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies](https://reader033.fdocuments.us/reader033/viewer/2022052702/56814406550346895db09a5f/html5/thumbnails/14.jpg)
Evolution of Radio Quiet AGN
![Page 15: General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies](https://reader033.fdocuments.us/reader033/viewer/2022052702/56814406550346895db09a5f/html5/thumbnails/15.jpg)
Using Chandra Deep Field Observations to Study AGN Evolution
![Page 16: General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies](https://reader033.fdocuments.us/reader033/viewer/2022052702/56814406550346895db09a5f/html5/thumbnails/16.jpg)
Using Chandra Deep Field Observations to Study AGN Evolution
N Counts
0 500 1000 1500 20001.0
10.0
100.0
1000.0N
umbe
r of
Sou
rces
> N
Cou
nts
CDF - S, z > 1.5CDF - N, z > 1.5
CDF - SCDF - N
![Page 17: General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies](https://reader033.fdocuments.us/reader033/viewer/2022052702/56814406550346895db09a5f/html5/thumbnails/17.jpg)
Using Chandra Deep Field Observations to Study AGN Evolution
Source Selection
Selected the radio-quiet AGN from the CDF surveys with Nph (0.5-8 keV) > 200 cnts (~130 sources with z > 0.5)
Radio loud objects were filtered out using R = f5GHz/f4400A > 10 Afonso et al. (2006), Richards (2000)
(~22/152 RLQs, ~14%).
Spectral Analysis 200 < Nph < 600 Cash statistic Nph > 600 2 statistic Model : Absorbed power-law Fitting range: (a) 0.5-7keV observed frame (b) 2-10keV rest frame
![Page 18: General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies](https://reader033.fdocuments.us/reader033/viewer/2022052702/56814406550346895db09a5f/html5/thumbnails/18.jpg)
Using Chandra Deep Field Observations to Study AGN Evolution
![Page 19: General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies](https://reader033.fdocuments.us/reader033/viewer/2022052702/56814406550346895db09a5f/html5/thumbnails/19.jpg)
Using Chandra Deep Field Observations to Study AGN Evolution
![Page 20: General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies](https://reader033.fdocuments.us/reader033/viewer/2022052702/56814406550346895db09a5f/html5/thumbnails/20.jpg)
Using Chandra Deep Field Observations to Study AGN Evolution
Histograms of and NH
<> = 1.64 +/- 0.34
<> ~ 2.6 x 1022 cm-2
![Page 21: General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies](https://reader033.fdocuments.us/reader033/viewer/2022052702/56814406550346895db09a5f/html5/thumbnails/21.jpg)
Using Chandra Deep Field Observations to Study AGN Evolution
Correlation Results:
- L(2-10 keV) & 1.6 < z < 3.3Spearman:rc = 0.57 P(r > rc) = 7.1 x 10-4
Pearson:r = 0.55P(r > rc) = 1.1 x 10-3
- L(2-5 keV) & 1.6 < z < 3.3Spearman:rc = 0.59 P(r > rc) = 4.3 x 10-4
Pearson:re = 0.61P(r > re) = 2.3 x 10-4
All spectral fits performed in the 0.5-7 keV observed frame
![Page 22: General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies](https://reader033.fdocuments.us/reader033/viewer/2022052702/56814406550346895db09a5f/html5/thumbnails/22.jpg)
Using Chandra Deep Field Observations to Study AGN Evolution
Correlation Results:
- L(2-10 keV) & 1.6 < z < 3.3Spearman:rc = 0.43 P(r > rc) = 2.4 x 10-2
Pearson:rc = 0.49 P(r > rc) = 7.6 x 10-3
- L(2-5 keV) & 1.6 < z < 3.3Spearman:rc = 0.54 P(r > rc) = 2.9 x 10-3
Pearson:rc = 0.61 P(r > rc) = 5.8 x 10-4
All spectral fits performed in the 2-10 keV rest-frame
![Page 23: General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies](https://reader033.fdocuments.us/reader033/viewer/2022052702/56814406550346895db09a5f/html5/thumbnails/23.jpg)
Using Chandra Deep Field Observations to Study AGN Evolution
![Page 24: General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies](https://reader033.fdocuments.us/reader033/viewer/2022052702/56814406550346895db09a5f/html5/thumbnails/24.jpg)
Using Chandra Deep Field Observations to Study AGN Evolution
Correlation Results:
- L(2-10 keV) & 1.6 < z < 3.3Spearman (1e43 - 5e45erg/s):rc = 0.6 P(r > rc) = 5 x 10-7
Pearson (1e43 - 2e45erg/s):rc = 0.51 P(r > rc) = 1.4 x 10-4
![Page 25: General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies](https://reader033.fdocuments.us/reader033/viewer/2022052702/56814406550346895db09a5f/html5/thumbnails/25.jpg)
Using Chandra Deep Field Observations to Study AGN Evolution
€
LX
=η ˙ M c2 ∝ M (˙ M
M)∝ M (
˙ M ˙ M Edd
)∝ M ˙ m
Possible Interpretations of the LX - Correlation
First Interpretation• Narrow range of M at high z• Large range of accretion rate•
Second Interpretation• Narrow range of accretion rate at high z• Large range in M• €
LX ∝ ˙ m
€
LX ∝ M
![Page 26: General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies](https://reader033.fdocuments.us/reader033/viewer/2022052702/56814406550346895db09a5f/html5/thumbnails/26.jpg)
Using Chandra Deep Field Observations to Study Quasar Evolution
Physical Interpretations of LX -
• Hot corona model by Haardt et al. 1997predicts that
increases with of the corona decreases with T of the corona
• If the corona is dominated by electron-positron pairs this model alsopredicts that
Log Lx
![Page 27: General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies](https://reader033.fdocuments.us/reader033/viewer/2022052702/56814406550346895db09a5f/html5/thumbnails/27.jpg)
Conclusions
• We confirm the Lx - correlation for radio quiet AGN at high z based on the spectral analysis of the CDF surveys.
• We find that the strength of Lx - correlation is z dependent and peaks at z ~ 2.2
• The Hot Corona model predicts the Lx - correlation
• The redshift dependence of the correlation suggests that quasars near the peak of their comoving number density are accreting near Eddington and have different accretion properties than their low-z counterparts
![Page 28: General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies](https://reader033.fdocuments.us/reader033/viewer/2022052702/56814406550346895db09a5f/html5/thumbnails/28.jpg)
Under the assumptions:
(a) that high-z quasars emit near Eddington
(b) that the optical depth of the corona is dominated by electron-positron pairs.
(c) The observed range in luminosity is due to a range in BH masses (~ 2-3 orders of magnitude)
the hot corona model of Haardt & Maraschi 1993 predicts :
log[L(2-10keV)]
The redshift dependence of the correlation implies that quasars near the peak of their comoving number density are accreting near Eddington and have different accretion properties than their low-z counterparts
Evolution of Radio Quiet Quasars
Possible Interpretation of -Lx is based on the hot corona model (Haardt & Maraschi 1993, Haardt, Maraschi, & Ghisellini 1997)
![Page 29: General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies](https://reader033.fdocuments.us/reader033/viewer/2022052702/56814406550346895db09a5f/html5/thumbnails/29.jpg)
Conclusions
(a) The spectral slope of the 1.4 < z < 4 radio-loud quasars appears not to vary significantly over 4 orders of magnitude in 2-10 keV luminosity. We do not find a significant correlation between the spectral slope and X-ray luminosity as found in our 1.5 < z < 4 radio-quiet quasar sample.
(b) The spectral slopes of the radio-loud quasars of the sample are significantly flatter than those of the radio-quiet sample possibly due to contamination from jet emission.
(c) The limited number of quasars in the present sample combined with the medium S/N of several of the observations may have led to an unaccounted for systematic effect. Additional observations of z ~ 2 lensed radio-loud quasars with better S/N will allow us to obtain tighter constraints on a possible correlation between and X-ray luminosity.
(d) The X-ray variability of the high redshifts radio-loud quasars of our sample is consistent with the known correlation between excess variance and luminosity observed in NLS1s when extrapolated to the larger luminosities of the present sample.
![Page 30: General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies](https://reader033.fdocuments.us/reader033/viewer/2022052702/56814406550346895db09a5f/html5/thumbnails/30.jpg)
CREDITS
DirectorGeorge Chartas
ActorsXinyu Dai
Michael Eracleous
Digital Camera PersonnelGordon Garmire
![Page 31: General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies](https://reader033.fdocuments.us/reader033/viewer/2022052702/56814406550346895db09a5f/html5/thumbnails/31.jpg)
Haardt, Maraschi, & Ghisellini (1997) predicted:
increases with , the optical depth of the Compton scattering.
decreases with T, the temperature of the corona.
Model Predictions
Optical Depth of IC Scattering
Temperature of Corona
![Page 32: General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies](https://reader033.fdocuments.us/reader033/viewer/2022052702/56814406550346895db09a5f/html5/thumbnails/32.jpg)
• Haardt, Maraschi, & Ghisellini (1997) also predicted:
In COMPACT CORONA, where the pair production dominates, Log Lx
• This is similar to what we have observed.
In a “Compact” Corona
![Page 33: General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies](https://reader033.fdocuments.us/reader033/viewer/2022052702/56814406550346895db09a5f/html5/thumbnails/33.jpg)
Two Possible Interpretations of the Correlation
€
LX
=η ˙ M c2 ∝ M (˙ M
M)∝ M (
˙ M ˙ M Edd
)∝ M ˙ m
• Narrow range (of order a few) of M at high redshift.
• Large range of .
First Interpretation
m&
∝→∝ mLX &
![Page 34: General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies](https://reader033.fdocuments.us/reader033/viewer/2022052702/56814406550346895db09a5f/html5/thumbnails/34.jpg)
• Opposite. The range is narrow, close to Eddington limits, and M range is large.
• The lc is the “compactness” of the corona.
• Haardt & Maraschi (1993) predicted that M lc, increases as lc increases.
Second Interpretation
lc (Coronal Compactness)
m&
€
LX ∝ M ∝ lc → τ ∝ Γ
• Consistent with semianlyti-cal model of Hauffmann & Haehnelt (2000) for the cosmological evolution of super massive black hole and their fueling rates.
![Page 35: General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies](https://reader033.fdocuments.us/reader033/viewer/2022052702/56814406550346895db09a5f/html5/thumbnails/35.jpg)
Evolution of Radio Quiet Quasars
• We recently presented results from a survey of relatively high redshift (1.5<z<4) gravitationally lensed radio-quiet quasars (RQQs) observed with the Chandra and
XMM-Newton (Dai et al. 2004).
![Page 36: General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies](https://reader033.fdocuments.us/reader033/viewer/2022052702/56814406550346895db09a5f/html5/thumbnails/36.jpg)
• Using gravitational lensing as a tool to study the evolution of distant quasars
• Gravitationally Lensed High-z Radio Quiet Quasars
Near Eddington Luminosites at redshifts above z~1.5
• High-z Radio Quiet Quasars from the Chandra Deep Field Surveys
• Conclusions
Evolution of Quasars
![Page 37: General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies](https://reader033.fdocuments.us/reader033/viewer/2022052702/56814406550346895db09a5f/html5/thumbnails/37.jpg)
Gravitational lensing as a tool to study AGN evolution
Conceptual diagram of the gravitational deflection of light in a quad GL system.
![Page 38: General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies](https://reader033.fdocuments.us/reader033/viewer/2022052702/56814406550346895db09a5f/html5/thumbnails/38.jpg)
Understanding the Evolution of Quasars
Soft photons
IC scatteringBlack Hole
Accretion Disc
Corona
Corona
![Page 39: General Assembly of IAU, Symposium #238 Black Holes: From Stars to Galaxies](https://reader033.fdocuments.us/reader033/viewer/2022052702/56814406550346895db09a5f/html5/thumbnails/39.jpg)
Using Chandra Deep Field Observations to Study AGN Evolution
Histograms of Lx and z