flare emisson from sagittarius a* across different
TRANSCRIPT
uni koelnFlare emisson from Sagittarius A* across different
spectral domains
Prpbing Strong Gravity near Black Holes 15-18, February, 2010, Prague, Czech Republic
Andreas Eckart I.Physikalisches Institut der Universität zu Köln
Max-Planck-Institut für Radioastronomie, Bonn
Outline
Orbits of High Velocity Stars in the Central Arcsecond
Eckart & Genzel 1996/1997 (first proper motions) Eckart et al. 2002 (S2 is bound; first elements) Schödel et al. 2002, 2003 (first detailed elements) Ghez et al 2003 (detailed elements) Eisenhauer 2005 (improved elements and distance)
~4 million solar masses at a distance of
~8 kpc
NIR flare emission – probing strong gravity
NIR K-band Flare Rate The observed K-band rate of 4-8 flares brighter than about 3 mJy is consdistent with the upper limit on the characteristic frequency of flares from light curve modeling (Meyer et al. 2009);
Red noise: Do et al. 2008; Pechacek et al. 2008; Eckart et al. 2006;
NIR K-band Flare Rate
Meyer; Do.; Ghez; Morris; Yelda; Schödel; Eckart, 2009, ApJ 694, L87 : characteristic time scale of 154 (+124,-87) minutes gives a lower limit on the flare rate of about 5 flares per day.
Red noise: Do et al. 2008; Pechacek et al. 2008; Eckart et al. 2006;
Hornstein et al . 2007
Gillessen et al. 2006
3σ values as upper limits for the contribution of SgrA*
IQ fluxes
Eisenhauer et al. 2005
Ghez et al. 2005
Eckart et al. 2005; Liu et al. 2006 exponential cut-off in the MIR
Steep NIR Spectra of SgrA* Flares
see: 3C 293: Floyd et al. 2006, M87: Perlman et al. 2001; Perlman & Wilson 2005; 3C 273: Jester et al. 2001, 2005
Steep NIR Spectra of SgrA* Flares
Yusef-Zadeh et al. 2009: red line spectral index -0.6 (dashed -4, -2, 2, 4)
Hornstein et al . 2007
Gillessen et al. 2006
3σ values as upper limits for the contribution of SgrA*
IQ fluxes
Eisenhauer et al. 2005
Ghez et al. 2005
Eckart et al. 2005; Liu et al. 2006 exponential cut-off in the MIR
Steep NIR Spectra of SgrA* Flares
see: 3C 293: Floyd et al. 2006, M87: Perlman et al. 2001; Perlman & Wilson 2005; 3C 273: Jester et al. 2001, 2005
The SSC model works!
Cross Correlation between the 2005 NIR and X-ray Flare
Flare emission originates from within <10mas form the position of SgrA*
2003 data: Eckart, Baganoff, Morris, Bautz, Brandt, et al. 2004 A&A 427, 1 2004 data: Eckart, Morris, Baganoff, Bower, Marrone et al. 2006 A&A 450, 535
see also Yusef-Zadeh, et al. ApJ 644, 198
2004
~6mJy
~225nJy
φ2/I and φ4/IV are dominated by a decaying flank; φ3/III is domainated by a rising flare flank.
Time lags are less <10-15 minutes
NIR and X-ray flares are well correlated.
Simultaueous NIR/X-ray Flare emission 2004
Indication for source component expansion: Expansion by 30% explains the difference between the NIR and X-ray flare structure.
2 flare phases φ3 φ4
SSC disk modeling of individual flares: 2004
Eckart et al. 2009; A&A 500, 395
Indication for Adiabatic Expansion of Synchrotron Source
Peak Flux Density 10 Jy
Peak Frequency 1.64 THz Assumed
Expansion Velocity V = 0.008 c
Eckart et al. 2009 A&A 500, 395
Adiabatic Expansion of a Single Synchrotron Source Component
Expansion spped Close to the disk: Yuan et al. 2008 Liu et al. 2006
See also Yusef-Zadeh et al.
2006-2009
Adiabatic Expansion Model for the 7 July 2004 Flare
A total of 3-6 source components allow for a complete fit of the variable part
of the SMA and VLA data.
We find 0.005c as a suitable expansion velocity - consistent with Yusef-Zadeh’s
values of 0.003-0.1 c and Yuan et al. 2008
2004: First Quasi Simultaneous X-ray/NIR/radio measurements
Eckart et al. 2009; A&A 500, 395
1.5 –2 hours
VLT UT4 L-band
APEX 1.3 mm v(exp) = 0.006 c
SgrA* on 3 June 2008: VLT L-band and APEX sub-mm measurements
Eckart et al. 2008; A&A 492, 337 1.5 – 2 hours lag between NIR/sub-mm
A Combined SSC and Adiabatic
Expansion Model
2007
Porquet et al. 2008 Dodds-Eden et al. 2009 Yusef-Zadeh et al. 2009
Sabha et al. 2009
High Power X-ray Flare
Porquet et al. 2008; Dodds-Eden et al. 2009; Yusef-Zadeh et al. 2009; Sabha et al. 2009
Dodds-Eden et al. 2009
High Power X-ray Flare
During and after flares the spots expand to meet the accretion flow density of about 10^7cm−3 at an approximate radius of 1000 Rs. The edge of the 1.4” FWHM size Bondi sphere is located at a radius of about 8x10^4Rs for a 4x10^6 solar mass SMBH (Baganoff et al. 2001, 2003).
Marscher 1983
7 -3
High Power X-ray Flare A Combined SSC and Adiabatic Expansion Model
2007
High Power X-ray Flare: VLT
High Power X-ray Flare: XMM
)2(2)32(2)( ++−∝ αα ν θ mkeV SSC SES
X-ray scattering efficiency:
High Power X-ray Flare: Model SSC X-ray scattering efficiency: low high low
axisymmetric wave oscillation e.g. Chan et al. 2009
differentially rotating disk
1991, 1998
230 GHz 43 GHz 43 GHz
unrelated
ξ
Low Level Emission from SgrA*
Synchrotron emission may be responsible for low level activity as well
Sabha et al. 2010 see poster C01 by Nadeen Sabha
on extreme luminosity states of SgrA*
The Central S-star Cluster 23 September 2004
Low Flux Density Phase
Sabha et al. 2010
23 September 2004; 2mJy upper limit
a) low-pass filtering the image; b) iterative identification and removal of individual stars; c) automatic point spread function (PSF) subtraction
PSFs via star finder from stars within the central few arcseconds
Subtraction of stars within R<0.7’’
Subtraction of stars within R<0.7’’
Subtraction of stars
23 September 2004 2mJy upper limit
The Central S-star Cluster (R<0.7’’)
Sabha et al. 2010
similar to KLF slope of 0.21+-0.02
for (R < 6′′) ; Buchholz et al. (2009) Γ=0.2+-0.05 consistent with
Do et al. (2009) & Buchholz et al. (2009).
Γ−=Σ RR)(1.03.0 log log
±= sKd
Nd
In a circular aperture of diameter 66 mas diameter (5 pixels ~1 resolution element) we measure a de-reddened flux densities
(using AK = 2.8)
1.5+-0.4 mJy, 1.3+-0.3 mJy, and 1.3+-0.2 mJy
for the low-pass filtering, iterative, and automatic PSF subtraction method.
Low Flux Density Phase
In the 23 September 2004 data there is no clear detection of a source at that position.
If the observed flux density limit is fully attributed to SgrA* this corresponds to a clear non-detection of any point
source at that position with a flux density limit of (value + 3σ)
2.4 mJy for SgrA* (dereddened).
Low Flux Density Phase
If all of it is stellar then the upper limit is defined by the uncertainty of the measurement and the limit for a
flux density from a non-stellar source at the position of SgrA* is
0.9 mJy (3σ, de-reddened).
While our data does not allow us to confirm the existance of a constant quiescent state our flux density limit is consistent
with the flux given by Do et al. (2009a) (1.75+-0.36 with Ak=3.3, 1.1+-0.2 with Ak=2.8)
Low Flux Density Phase
Low Flux Density Phase
Sabha et al. 2010
‘Quescent flux limit‘ Cannot be matched via Bremsstrahlung but can be matched
easily in a SSC spotted disk model.
Polarized NIR Emission from SgrA*: The sub-flares are polarized!
Significance of polarized flares against red noise
indication for strong gravity
VLT NACO Wollaston prism plus retarder wave-plate
Eckart, Schödel, Meyer Trippe, Ott, Genzel 2006, A&A 455, 1
2005 NIR Polarized Flux Density from SgrA*
see poster B01 on precision of NIR polarimetry by Gunther Witzel
Goldston, Quataert & Igumenshchev 2005, ApJ 621, 785
see also Broderick & Loeb 2005 astro-ph/0509237 Broderick & Loeb 2005 astro-ph/0506433
Dovciak, Karas & Yaqoob 2004, ApJS 153, 205 Dovciak et al. 2006 ~4min prograde
~30min static ~60min retrograde for 3.6x10**6Msol
NIR Polarized Flux Density from SgrA*
total intensity
polarization angle
polarization degree
Zamaninasab et al. 2009talk by Mohammad Zamaninasab
1σ 3σ 5σ
Zamaninasab et al. 2009
Zamaninasab et al. 2009
13 June 2004
Polarized flares as the signature of strong gravity are significant against randomly polarized
red noise
Meyer, Schödel, Eckart, Karas, Dovciak, Duschl 2006b Meyer, Eckart, Schödel, Duschl, Muzic, Dovciak, Karas 2006a
Eckart, Schödel, Meyer, Ott, Trippe, Genzel 2006
1σ
3σ
χ analysis indicates a= 0.4-1 i=50 -70
2
QPOs as repeatedly occurring signature of strong gravity in
a spotted disk with sveral spots brightest close to the ISCO?
1.5 –2 hoursL-band
APEX 1.3 mm
v(exp) = 0.006 c
SgrA* on 3 June 2008: VLT L-band and APEX sub-mm measurements
Eckart et al. 2008; A&A 492, 337 Garcia-Marin et al.2009
mean time difference between sub-flares: 25+-5 minutes
SgrA* VLT/APEX flare on 3 June 2008: NIR data-model: sub-flare structure
L`-band K-band
4 million solar masses
Gierlinski et al. 2008
A ~1 h X-ray periodicity in an active galaxy RE J1034+396
a few 10 million solar masses
The Overall Picture: Indications for a Wind or Outflow?
Towards a Combined Source Model for SgrA*
see poster B07 by Monica Valencia-S. on the special low luminosity nucleus IRAS01072+4954
CARMA mm-continuum and VLT NIR/MIR images of the mini-spiral
Kunneriath et al. 2010 in prep.
CARMA 1 and 3 mm-continuum spectral index of the mini-spiral
Kunneriath et al. 2010 in prep.
Muzic,Eckart, Schödel, Meyer et al. 2007 A&A 469, 993
Proper Motion of Thin Filaments at the GC
Besides the Mini-Cavity – the comerary sources are the strongest
indication for a fast wind from SgrA*!
X7 polarized with 30% at PA -34+-10 Mie bow-shock symmetry along PA 56+-10
includes direction towards SgrA*
Muzic,Eckart, Schödel et al. 2007, A&A, 469, 993 and 2009
Cometary Sources: Shaped by a Wind from SgrA*?
polarization
Muzic, Eckart, Schödel et al. 2007 A&A 469, 993
Sabha, Eckart, Witzel, et al. 2009
Sketch of an Outflow Model: The Combined Wind from the Cluster of Hot Stars and SgrA*
5“/200 mpc
SgrA*: Emission from a disk with a short jet
•Orbiting spot model describes successfully the observed flare variability
•In polarized light the signature of strong gravity represents a statistically significant feature measured against randomly polarized red noise.
•QPOs may just appear as repeated signatures of strong gravity in a temporary spotted disk.
•SSC model with THz peaked synchrotron spectra plus adiabatic expansion described successfully the SgrA* variability.
•Low expansion velocities imply expansion within the accretion disk, flaring of a disk corona, and/or expansion of a component with additional bulk velocity.
Summary
I.Physikalisches Institut
LBT: LINC-NIRVANA MPIA Heidelberg Arcetri Florence, Uni of Cologne, MPIfR Bonn
Large Bincular Telscope In Arizona 2x8.4m Spiegel
LBT ‘pre-assembly‘ 27 Juni 2001, Ansaldo Energia, Milano
Astronomer
Straubmeier, Bertram, Zuther, Eckart Cologne provides: Dewar, FFTS, and cooling system
I.Physikalisches Institut
LBT: LINC/NIRVANA
Sagittarius A*
with theVLTI
IRS3 and IRS7: Pott, Eckart, Glindemann, et al., 2008, A&A 487, 413 Pott, Eckart, Glindemann, et al., 2008, A&A 480, 115
First VLTI Measurements on the stars IRS7 and IRS3
in the Galactic Center by the Cologne Group
I.Physikalisches Institut
VLTI: GRAVITY
Straubmeier, Eckart
JWST successor of HST
MIRI JWST Consortium G. Wright Edinburg
Cologne is the only German University Institute that contributes to JWST
ESO E-ELT In the METIS project Cologne actively contributes to preparation of E-ELT instrumentation
The Galactic Center is a unique laboratory in which one can study
physics in the vicinity of large masses
LBT NIR/OPT Beam Combiner: Universitity of Cologne MPIA, Heidelberg Osservatorio Astrofisico di Arcetri MPIfR Bonn
ESO ESO E-ELT
Cologne contribution to MIRI on JWST
JWST
Foliennummer 20
Foliennummer 21
High Power X-ray Flare A Combined SSC and Adiabatic Expansion Model
Foliennummer 23
Foliennummer 24
Foliennummer 25
Foliennummer 26
Foliennummer 27
Foliennummer 34
Foliennummer 35
Foliennummer 36
Pattern of a spot orbiting at the ISCO
Pattern recognition against polarized red noise
Pattern recognition against polarized red noise
Foliennummer 44
Foliennummer 45
Foliennummer 46
Foliennummer 47
Foliennummer 48
Foliennummer 49
Foliennummer 50
Foliennummer 51
Foliennummer 52
Foliennummer 53
Foliennummer 54
Foliennummer 55
Foliennummer 56
Foliennummer 57
Foliennummer 58
Foliennummer 59
Foliennummer 60
Foliennummer 61
Foliennummer 62
Foliennummer 63
Foliennummer 64
Foliennummer 65
Foliennummer 66
Foliennummer 67
Foliennummer 68
Foliennummer 69
Prpbing Strong Gravity near Black Holes 15-18, February, 2010, Prague, Czech Republic
Andreas Eckart I.Physikalisches Institut der Universität zu Köln
Max-Planck-Institut für Radioastronomie, Bonn
Outline
Orbits of High Velocity Stars in the Central Arcsecond
Eckart & Genzel 1996/1997 (first proper motions) Eckart et al. 2002 (S2 is bound; first elements) Schödel et al. 2002, 2003 (first detailed elements) Ghez et al 2003 (detailed elements) Eisenhauer 2005 (improved elements and distance)
~4 million solar masses at a distance of
~8 kpc
NIR flare emission – probing strong gravity
NIR K-band Flare Rate The observed K-band rate of 4-8 flares brighter than about 3 mJy is consdistent with the upper limit on the characteristic frequency of flares from light curve modeling (Meyer et al. 2009);
Red noise: Do et al. 2008; Pechacek et al. 2008; Eckart et al. 2006;
NIR K-band Flare Rate
Meyer; Do.; Ghez; Morris; Yelda; Schödel; Eckart, 2009, ApJ 694, L87 : characteristic time scale of 154 (+124,-87) minutes gives a lower limit on the flare rate of about 5 flares per day.
Red noise: Do et al. 2008; Pechacek et al. 2008; Eckart et al. 2006;
Hornstein et al . 2007
Gillessen et al. 2006
3σ values as upper limits for the contribution of SgrA*
IQ fluxes
Eisenhauer et al. 2005
Ghez et al. 2005
Eckart et al. 2005; Liu et al. 2006 exponential cut-off in the MIR
Steep NIR Spectra of SgrA* Flares
see: 3C 293: Floyd et al. 2006, M87: Perlman et al. 2001; Perlman & Wilson 2005; 3C 273: Jester et al. 2001, 2005
Steep NIR Spectra of SgrA* Flares
Yusef-Zadeh et al. 2009: red line spectral index -0.6 (dashed -4, -2, 2, 4)
Hornstein et al . 2007
Gillessen et al. 2006
3σ values as upper limits for the contribution of SgrA*
IQ fluxes
Eisenhauer et al. 2005
Ghez et al. 2005
Eckart et al. 2005; Liu et al. 2006 exponential cut-off in the MIR
Steep NIR Spectra of SgrA* Flares
see: 3C 293: Floyd et al. 2006, M87: Perlman et al. 2001; Perlman & Wilson 2005; 3C 273: Jester et al. 2001, 2005
The SSC model works!
Cross Correlation between the 2005 NIR and X-ray Flare
Flare emission originates from within <10mas form the position of SgrA*
2003 data: Eckart, Baganoff, Morris, Bautz, Brandt, et al. 2004 A&A 427, 1 2004 data: Eckart, Morris, Baganoff, Bower, Marrone et al. 2006 A&A 450, 535
see also Yusef-Zadeh, et al. ApJ 644, 198
2004
~6mJy
~225nJy
φ2/I and φ4/IV are dominated by a decaying flank; φ3/III is domainated by a rising flare flank.
Time lags are less <10-15 minutes
NIR and X-ray flares are well correlated.
Simultaueous NIR/X-ray Flare emission 2004
Indication for source component expansion: Expansion by 30% explains the difference between the NIR and X-ray flare structure.
2 flare phases φ3 φ4
SSC disk modeling of individual flares: 2004
Eckart et al. 2009; A&A 500, 395
Indication for Adiabatic Expansion of Synchrotron Source
Peak Flux Density 10 Jy
Peak Frequency 1.64 THz Assumed
Expansion Velocity V = 0.008 c
Eckart et al. 2009 A&A 500, 395
Adiabatic Expansion of a Single Synchrotron Source Component
Expansion spped Close to the disk: Yuan et al. 2008 Liu et al. 2006
See also Yusef-Zadeh et al.
2006-2009
Adiabatic Expansion Model for the 7 July 2004 Flare
A total of 3-6 source components allow for a complete fit of the variable part
of the SMA and VLA data.
We find 0.005c as a suitable expansion velocity - consistent with Yusef-Zadeh’s
values of 0.003-0.1 c and Yuan et al. 2008
2004: First Quasi Simultaneous X-ray/NIR/radio measurements
Eckart et al. 2009; A&A 500, 395
1.5 –2 hours
VLT UT4 L-band
APEX 1.3 mm v(exp) = 0.006 c
SgrA* on 3 June 2008: VLT L-band and APEX sub-mm measurements
Eckart et al. 2008; A&A 492, 337 1.5 – 2 hours lag between NIR/sub-mm
A Combined SSC and Adiabatic
Expansion Model
2007
Porquet et al. 2008 Dodds-Eden et al. 2009 Yusef-Zadeh et al. 2009
Sabha et al. 2009
High Power X-ray Flare
Porquet et al. 2008; Dodds-Eden et al. 2009; Yusef-Zadeh et al. 2009; Sabha et al. 2009
Dodds-Eden et al. 2009
High Power X-ray Flare
During and after flares the spots expand to meet the accretion flow density of about 10^7cm−3 at an approximate radius of 1000 Rs. The edge of the 1.4” FWHM size Bondi sphere is located at a radius of about 8x10^4Rs for a 4x10^6 solar mass SMBH (Baganoff et al. 2001, 2003).
Marscher 1983
7 -3
High Power X-ray Flare A Combined SSC and Adiabatic Expansion Model
2007
High Power X-ray Flare: VLT
High Power X-ray Flare: XMM
)2(2)32(2)( ++−∝ αα ν θ mkeV SSC SES
X-ray scattering efficiency:
High Power X-ray Flare: Model SSC X-ray scattering efficiency: low high low
axisymmetric wave oscillation e.g. Chan et al. 2009
differentially rotating disk
1991, 1998
230 GHz 43 GHz 43 GHz
unrelated
ξ
Low Level Emission from SgrA*
Synchrotron emission may be responsible for low level activity as well
Sabha et al. 2010 see poster C01 by Nadeen Sabha
on extreme luminosity states of SgrA*
The Central S-star Cluster 23 September 2004
Low Flux Density Phase
Sabha et al. 2010
23 September 2004; 2mJy upper limit
a) low-pass filtering the image; b) iterative identification and removal of individual stars; c) automatic point spread function (PSF) subtraction
PSFs via star finder from stars within the central few arcseconds
Subtraction of stars within R<0.7’’
Subtraction of stars within R<0.7’’
Subtraction of stars
23 September 2004 2mJy upper limit
The Central S-star Cluster (R<0.7’’)
Sabha et al. 2010
similar to KLF slope of 0.21+-0.02
for (R < 6′′) ; Buchholz et al. (2009) Γ=0.2+-0.05 consistent with
Do et al. (2009) & Buchholz et al. (2009).
Γ−=Σ RR)(1.03.0 log log
±= sKd
Nd
In a circular aperture of diameter 66 mas diameter (5 pixels ~1 resolution element) we measure a de-reddened flux densities
(using AK = 2.8)
1.5+-0.4 mJy, 1.3+-0.3 mJy, and 1.3+-0.2 mJy
for the low-pass filtering, iterative, and automatic PSF subtraction method.
Low Flux Density Phase
In the 23 September 2004 data there is no clear detection of a source at that position.
If the observed flux density limit is fully attributed to SgrA* this corresponds to a clear non-detection of any point
source at that position with a flux density limit of (value + 3σ)
2.4 mJy for SgrA* (dereddened).
Low Flux Density Phase
If all of it is stellar then the upper limit is defined by the uncertainty of the measurement and the limit for a
flux density from a non-stellar source at the position of SgrA* is
0.9 mJy (3σ, de-reddened).
While our data does not allow us to confirm the existance of a constant quiescent state our flux density limit is consistent
with the flux given by Do et al. (2009a) (1.75+-0.36 with Ak=3.3, 1.1+-0.2 with Ak=2.8)
Low Flux Density Phase
Low Flux Density Phase
Sabha et al. 2010
‘Quescent flux limit‘ Cannot be matched via Bremsstrahlung but can be matched
easily in a SSC spotted disk model.
Polarized NIR Emission from SgrA*: The sub-flares are polarized!
Significance of polarized flares against red noise
indication for strong gravity
VLT NACO Wollaston prism plus retarder wave-plate
Eckart, Schödel, Meyer Trippe, Ott, Genzel 2006, A&A 455, 1
2005 NIR Polarized Flux Density from SgrA*
see poster B01 on precision of NIR polarimetry by Gunther Witzel
Goldston, Quataert & Igumenshchev 2005, ApJ 621, 785
see also Broderick & Loeb 2005 astro-ph/0509237 Broderick & Loeb 2005 astro-ph/0506433
Dovciak, Karas & Yaqoob 2004, ApJS 153, 205 Dovciak et al. 2006 ~4min prograde
~30min static ~60min retrograde for 3.6x10**6Msol
NIR Polarized Flux Density from SgrA*
total intensity
polarization angle
polarization degree
Zamaninasab et al. 2009talk by Mohammad Zamaninasab
1σ 3σ 5σ
Zamaninasab et al. 2009
Zamaninasab et al. 2009
13 June 2004
Polarized flares as the signature of strong gravity are significant against randomly polarized
red noise
Meyer, Schödel, Eckart, Karas, Dovciak, Duschl 2006b Meyer, Eckart, Schödel, Duschl, Muzic, Dovciak, Karas 2006a
Eckart, Schödel, Meyer, Ott, Trippe, Genzel 2006
1σ
3σ
χ analysis indicates a= 0.4-1 i=50 -70
2
QPOs as repeatedly occurring signature of strong gravity in
a spotted disk with sveral spots brightest close to the ISCO?
1.5 –2 hoursL-band
APEX 1.3 mm
v(exp) = 0.006 c
SgrA* on 3 June 2008: VLT L-band and APEX sub-mm measurements
Eckart et al. 2008; A&A 492, 337 Garcia-Marin et al.2009
mean time difference between sub-flares: 25+-5 minutes
SgrA* VLT/APEX flare on 3 June 2008: NIR data-model: sub-flare structure
L`-band K-band
4 million solar masses
Gierlinski et al. 2008
A ~1 h X-ray periodicity in an active galaxy RE J1034+396
a few 10 million solar masses
The Overall Picture: Indications for a Wind or Outflow?
Towards a Combined Source Model for SgrA*
see poster B07 by Monica Valencia-S. on the special low luminosity nucleus IRAS01072+4954
CARMA mm-continuum and VLT NIR/MIR images of the mini-spiral
Kunneriath et al. 2010 in prep.
CARMA 1 and 3 mm-continuum spectral index of the mini-spiral
Kunneriath et al. 2010 in prep.
Muzic,Eckart, Schödel, Meyer et al. 2007 A&A 469, 993
Proper Motion of Thin Filaments at the GC
Besides the Mini-Cavity – the comerary sources are the strongest
indication for a fast wind from SgrA*!
X7 polarized with 30% at PA -34+-10 Mie bow-shock symmetry along PA 56+-10
includes direction towards SgrA*
Muzic,Eckart, Schödel et al. 2007, A&A, 469, 993 and 2009
Cometary Sources: Shaped by a Wind from SgrA*?
polarization
Muzic, Eckart, Schödel et al. 2007 A&A 469, 993
Sabha, Eckart, Witzel, et al. 2009
Sketch of an Outflow Model: The Combined Wind from the Cluster of Hot Stars and SgrA*
5“/200 mpc
SgrA*: Emission from a disk with a short jet
•Orbiting spot model describes successfully the observed flare variability
•In polarized light the signature of strong gravity represents a statistically significant feature measured against randomly polarized red noise.
•QPOs may just appear as repeated signatures of strong gravity in a temporary spotted disk.
•SSC model with THz peaked synchrotron spectra plus adiabatic expansion described successfully the SgrA* variability.
•Low expansion velocities imply expansion within the accretion disk, flaring of a disk corona, and/or expansion of a component with additional bulk velocity.
Summary
I.Physikalisches Institut
LBT: LINC-NIRVANA MPIA Heidelberg Arcetri Florence, Uni of Cologne, MPIfR Bonn
Large Bincular Telscope In Arizona 2x8.4m Spiegel
LBT ‘pre-assembly‘ 27 Juni 2001, Ansaldo Energia, Milano
Astronomer
Straubmeier, Bertram, Zuther, Eckart Cologne provides: Dewar, FFTS, and cooling system
I.Physikalisches Institut
LBT: LINC/NIRVANA
Sagittarius A*
with theVLTI
IRS3 and IRS7: Pott, Eckart, Glindemann, et al., 2008, A&A 487, 413 Pott, Eckart, Glindemann, et al., 2008, A&A 480, 115
First VLTI Measurements on the stars IRS7 and IRS3
in the Galactic Center by the Cologne Group
I.Physikalisches Institut
VLTI: GRAVITY
Straubmeier, Eckart
JWST successor of HST
MIRI JWST Consortium G. Wright Edinburg
Cologne is the only German University Institute that contributes to JWST
ESO E-ELT In the METIS project Cologne actively contributes to preparation of E-ELT instrumentation
The Galactic Center is a unique laboratory in which one can study
physics in the vicinity of large masses
LBT NIR/OPT Beam Combiner: Universitity of Cologne MPIA, Heidelberg Osservatorio Astrofisico di Arcetri MPIfR Bonn
ESO ESO E-ELT
Cologne contribution to MIRI on JWST
JWST
Foliennummer 20
Foliennummer 21
High Power X-ray Flare A Combined SSC and Adiabatic Expansion Model
Foliennummer 23
Foliennummer 24
Foliennummer 25
Foliennummer 26
Foliennummer 27
Foliennummer 34
Foliennummer 35
Foliennummer 36
Pattern of a spot orbiting at the ISCO
Pattern recognition against polarized red noise
Pattern recognition against polarized red noise
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