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									        Fermilab Colloqium 29 October 2003

   Solving Quasars
                   part I
              in particular…
  Understanding Quasar Atmospheres


                 Martin Elvis
 Harvard-Smithsonian Center for Astrophysics



Elvis M., 2000, Astrophysical Journal 545, 63
                                                                      Fermilab Colloqium 29 October 2003


      Quasars* unsolved after 40 years
                             Discovered in 1963
         Quasars are the most powerful continuous
            radiation sources in the Universe
  Once were a `hot topic’
• Were the first to start the downfall of Steady State Cosmology
   – - via ‘evolution’: change in density with cosmic time
• Now astronomers have moved on to easier problems
   – – Large scale structure, Dark Energy and Gamma-ray bursts
• Quasar studies continue to generate many papers
                  • …but little understanding?

    * Note for the pedantic: By ‘quasars’ I mean all types of ‘activity’ in galaxies
                                                      Fermilab Colloqium 29 October 2003


                   What’s the problem?
We have no images of a quasar atmosphere
Would need 1000 times sharper pictures than Hubble or Chandra <100mas

Must rely on spectra: span all wavelengths: X-ray - optical - radio

• Enormous array of detail




      • Superficial
        understanding
                             Fermilab Colloqium 29 October 2003


       Why Study Quasars?

   We live on a planet
   A star gives us life
   Galaxies dominate the Universe
•   … but why do quasars matter?
•   Here are 4 answers:
                                           Fermilab Colloqium 29 October 2003

             1. An Astronomer’s Answer

Outside the wavelength range that our eyes are sensitive to
        Radio
                                        Gamma-ray


                Quasars dominate the night sky




                              X-ray
                                                 Fermilab Colloqium 29 October 2003


              2. An Astrophysicist’s Answer
Gravity powered, not fusion.
via Black Holes 106 - 109 as massive as the
   Sun. Gas heats up falling toward it, like a
   spacecraft on re-entry.
The power available from gravity for
   heating is all too obvious following the
   Columbia tragedy

Emit strongly from radio to g-rays.
   How do they do that?

Billions of times brighter than
  stars. Can outshine a whole galaxy

Make galaxy length jets
                       3. A Cosmologist’s Answer
Quasars lie at the hearts of galaxies:
  Galaxy mass and quasar black hole mass
  are tightly connected. Maggorrian et al, Ferrarese &
  Merritt, Gephardt et al.

How? Should be governed by different
  processes.

Emit up to 1/5 of power in Universe:
  Important input, may dominate in some
  places, times.

Already exist at t<1Gyr (z=6)
            FIRST survey discovery, Becker et al.


  ½ Gyr from WMAP reionization at z=20
  special role in early Universe?
  reionization, seeding galaxies…
  element creation, star formation catalyst via dust
  creation?
                                                         Fermilab Colloqium 29 October 2003

                            4. A Physicist’s Answer
Eject bulk gas at 99.50% speed of light
   G=10
similar to proton in Fermilab Tevatron     99.88%c
Impacts gas of intergalactic medium.->what emerges?
Accelerates e- to g~1000 -> TeV photons
X-rays come from region of Strong Gravity
seen in 6.4 keV `Fe-K’ (=Fe Lyman-a) emission line?
          MCG -6-30-15 (XMM)




                                           Reynolds C.
                      GR redshift?
                               6.4 keV   Reynolds C.




   Wilms et al., 2002, MNRAS, 328, L27
                                                               Fermilab Colloqium 29 October 2003

                                 What do we know?
          High level theory rapidly gave a clear picture



massive black hole
Lynden-Bell 1969



accretion disk
Lynden-Bell 1969, Pringle & Rees 1972,Shakura & Sunyaev 1972



relativistic jet
     Rees 1967 [PhD], Blandford & Rees 1974




        All established just 10 years after discovery
                                              Fermilab Colloqium 29 October 2003


    This theory describes a naked quasar
          does not connect to the atomic physics
               features observed in quasars




Leaves us with no way to order observations, nothing to test
                                                                 Fermilab Colloqium 29 October 2003

         Atomic features in Quasar Atmospheres




High ionization: e.g. CIV, OVI
Low ionization: e.g. MgII, Hb.




                            All studied separately with separate telescopes
Quasars have no temperature
                              Whipple 10 meter

                      Compton gamma-ray
                      Observatory


                              Chandra

                          Hubble


                                        MMT


                           Sub-millimeter array



                                     VLA
                                                          Fermilab Colloqium 29 October 2003
    Wall, Tree, Rope, Spear, Snake, Fan
Not having the complete picture can be misleading




 Blind men and the elephant. Manga VIII Hokusai, Katsushika (1760-1849)
                                                  Fermilab Colloqium 29 October 2003


               we need a ‘low theory’
    that deals with the multitude of quasar details
    These optically thin features are all interconnected
               S = `quasar atmosphere’
•   Just as there are textbooks on ‘Stellar Atmospheres’
•   we need the subject of ‘Quasar Atmospheres’
•   Takes more than 1 step.
•   First build an observational paradigm
     i.e. what do the observations drive require of any theory?
                                                                          Fermilab Colloqium 29 October 2003

   A Paradigm for Quasar Atmospheres
                  Elvis M., 2000, Astrophysical Journal 545, 63
                  A Geometric & Kinematic solution
                         c.f. Rees relativistic jets for blazars/radio sources


                                                                                 Quasar Atmosphere
Accelerating bi-conical wind
                                        hollow cone
Broad Absorption Lines
                                       no absorption
Reflection features                                                   NB: Independent of Unification
                                           lines                           Jets are not included
  Thin Vertical wind                                                      Supermassive black hole
 Narrow absorption lines
 X-ray `warm’ absorbers
                                                                                  Accretion disk
  Broad Emission Lines

                                                                     X-ray/UV ionizing continuum

  Can now re-construct this model using data not in Elvis 2000
                                                        Princeton AGN Physics with the SDSS, 29 July 2003

        Take a lesson from lab plasmas: use all the data
2mm interferometer
X-ray PHA
                                  NSTX diagnostic instruments cover everything
X-ray crystal spectrometer
Radiometer
                                                        NSTX at PPPL
Thomson scattering
                                                National Spherical Torus eXperiment
Far infrared tangential
                                                Princeton Plasma Physics Laboratory
Interferometer/polarimeter
Visible spectrometer
Vacuum UV survey spectrometer

Grazing incidence spectrometer
Tangential bolometer array
Single channel visible
Bremsstrahlung detector
Polarimeter
X-ray pinhole camera
Soft X-ray arrays
Fast tangential X-ray camera
Reflectometer array
Infrared cameras
                                                                                      Fermilab Colloqium 29 October 2003



     12,277 Papers on Quasars since 1963*
                  *ADS to 4/18/03, refereed only , search on abstract containing ‘quasar’ | ‘AGN’
         1/day.     Now 2 per day = 5% of all astronomy papers

                                              Spam!
•    Need filters---
    1. Physical measurements
         Mass, length, density. Not ratios, column densities
    2. Favor absorption: advice from Steve Kahn c.1985
         1-D spatial integral, not 3-D;
         blueshift = outflow
    3. Use Polarization
       Non-spherical geometry
•    With these filters just a dozen papers define the structure of quasar
                                  atmospheres.
                                                                               Fermilab Colloqium 29 October 2003

             1.Physical Measurements:
            BEL Velocity-radius relation
Reverberation mapping shows Keplerian velocity relation in BELs
                                         Peterson & Wandel 2000 ApJ 540, L13


                                                                   Mass
             Doppler width of em. Line




                                                                                        ~1000 rs,
                                                                                        Schwartzchild
                                                                                        radii


                                                       Light echo delay (days)
                                                                Pole-on


       Broad Emission Lines close to Keplerian velocities
                                                                                    Fermilab Colloqium 29 October 2003


               1.Physical Measurements: Angle
Use VLBI + X-ray to get angle of jet to line of sight Rokaki et al. 2003 astroph/0301405

 (1) Rotation about jet axis
 c.f. Wills & Browne 1986, Brotherton 1996,
       McLure & Jarvis 2003                                                                    FAST         Edge-
                                                                                                            on
 Ha polarization rotation also implies orbiting gas




                                                      Continuum/Ha flux
      Smith et al 2002
                                                                          Pole-on       Relativistic
(2) Continuum drops as cos q                                                            beaming

EW=EW0[1/3 cosq(1+2cosq)]-1 limb darkened disk                                           isotropic      Flat disk
                                                                                                       continuum
Ha does not 
Ha scale height larger than disklike                                      SLOW
  optical continuum
But BLR is rotating
   rotating                 cylinder?
                                                                       Rokaki et al. 2003 astro-ph/0301405
                                                                  Pole-on
 A highly non-equilibrium shape

                     Simplest solution: BLR is in a rotating wind
                                            Princeton AGN Physics with the SDSS, 29 July 2003


                    2. Absorption Features
                           Winds are common in quasars                                 new
                                                       Chandra HETG: 900ksec NGC3783




                                                                                       new
Narrow UV lines                                              Narrow X-ray lines

High ionization CIV, OVI                                 High ionization OVII,OVIII

                                                  Same Outflow ~1000 km s-1 new
Outflow ~1000 km   s-1
                                                      Seen in same 50% of quasars
Seen in 50% of quasars



                     Simplest solution: Same gas, 2 phases
                                                                           Fermilab Colloqium 29 October 2003

           2. Absorption: More Physics from X-rays
Krongold, Nicastro, Brickhouse, Elvis, Liedahl & Mathur, 2003 ApJ, in press. astro-ph/0306460

                        Chandra HETGS 850ksec spectrum of NGC 3783




            Over 100 absorption features fitted by a 6 parameter model
            One T~106 K and one T~104 K, in pressure balance to 5%

                        2-phase gas in pressure equilibrium
                                                              Fermilab Colloqium 29 October 2003


     2. Absorption: where is the wind?
                       Arav, Korista & de Kool 2002, ApJ 566, 699
             Arav, Korista, de Kool, Junkkarinen & Begelman 1999 ApJ 516, 27



• Velocity dependent
  covering factors
•  Absorber is close to
  continuum source
•  absorber is moving
  transverse



         Wind is close to continuum, crosses line of sight
                                                Fermilab Colloqium 29 October 2003


     A quasar wind is like a flame
               We are looking through a flow




 Apparent lack of change is a common handicap for astronomers
                       the ‘Static Illusion’
e.g. expansion of the Universe, cluster cooling flows, quasar disks
                                                              Fermilab Colloqium 29 October 2003


                Emission lines: a thin wind?
                        Leighly & Moore 2003, ApJ submitted

• Narrow Line Seyfert 1
  galaxies (NLSy1s) show
broad, strongly blueshifted
high ionization (CIV) lines
• Understandable as disk wind
• redshifted lines hidden by disk
• Low ionization lines from                                                 See: Gaskell 1982
                                                                                 Wilkes 1984
  outer disk c.f. Collin-Souffrin, Hameury
   & Joly,1988 A&A 205, 19
                                             Low ionization
                                                 MgII


                 BELs are rotating, transverse, thin winds
                                                            Fermilab Colloqium 29 October 2003

              2. Absorption / 1. Physical Measurements:
                       Wind Density,thickness
     Nicastro et al. 1999 ApJ, 512, 184                            X-ray continuum

    UV/X-ray absorption responds to
      continuum changes: photoionized                       time
                                          “OVII edge”
•  But responds with a delay
• = recombination/ionization time
•  density  ne~108 cm- 3 for OVIII
• ne~3x107 cm-3 for FeXVII                “OVIII edge”

    Absorbing wind is dense
     density + column density
     (~3x1022 cm-2)
                                                             wind
      thickness (~10       15 cm)             To Earth
                                                                              Black hole
     < distance to continuum               accretion disk
     Absorbing wind is narrow
                                                                    DR R
                                                     Fermilab Colloqium 29 October 2003



          3. Polarization: X-ray absorbers
                     Leighly et al. 1997 ApJ 489, L137

Absorption line quasars are highly
 polarized in optical:
1. Scattering off non-spherical
   distribution
   Edge-on    structure
2. Pole-on objects must be unobscured
        scatterer & obscurer:
       flattened & co-axial


                  Absorbers are seen edge-on
                                          Princeton AGN Physics with the SDSS, 29 July 2003


 Flattened, Transverse Wind  axisymmetry
                 Mathur, Elvis & Wilkes 1995 ApJ, 452, 230

A transverse wind suggests
  an axisymetric geometry:
          bi-cones
• looking edge-on see
  absorbers
• Wind does not hug disk
• pole-on: no absorbers
•  absorbers in all quasars




          Absorbing wind is a bi-cone to 1st order
                                                                         Fermilab Colloqium 29 October 2003


Putting X-ray/UV absorber and BEL together
                              Elvis 2000 ApJ 545, 63; Krongold et al. 2003

             Both are disk winds rising well above the disk plane

They share physical properties:
                                                    Similar Radius:                for NGC 5548
Similar Pressure:                                   r( abs ) ~1015 - 1018cm recomb. time + NHX
                                                    r(BELR)~1016cm    CIV reverberation mapping
P( abs )   ~1015   =   104   Kx   1011   cm-3
P(BELR)~1015 = 106 K x 109 cm-3
                                                                     Similar Temperatures
  Matching Ionization Parameter, U:                           new
                                                                     For low U absorber, BELs
  T/U( abs ) = 106 = T( abs ) ~106 K/ U( abs ) ~1

  T/U(BELR)= 106 = T( abs ) ~104 K/ U(BELR) 0.04

            Keep it simple: Emission and Absorption are
                 2 phases of the same quasar wind
                                                     Fermilab Colloqium 29 October 2003


         Components of Quasar Atmospheres




High ionization: e.g. CIV, OVI
Low ionization: e.g. MgII, Hb.

                                     United
                  In a 2-phase transverse wind in pressure balance
                                                                                          Fermilab Colloqium 29 October 2003

                            The Final Element:
                      Broad Absorption Lines (BALs)
10% of quasars show BALs with doppler widths ~2%c - 10%c
~10x NALs. Clear acceleration (or deceleration)

                                                                                              Ferland & Hamann 1999
                                                                                              Annual Reviews of
                                                                                              Astronomy & Astrophysics ,
                                                                                              37, 487
 QuickTime™ an d a TIFF (Unc ompress ed) decompre ssor ar e need ed to s ee this p icture .




             Old question: Special objects? or Special angle?
                                                   Princeton AGN Physics with the SDSS, 29 July 2003



           Broad Absorption Lines (BALs)
                     Lee & Turnshek 1995 ApJ 453 L61


• BEL FWHM correlates with
  BAL velocity (at minimum flux)
• V(BAL) ~ 2 FWHM(BEL)



  More BEL-BAL correlations:
  Reichard et al. 2003                 BEL width



                                                    BAL width

                         BAL gas knows about BEL gas
                                                      Fermilab Colloqium 29 October 2003


                BALs from a rotating wind
 Hall et al. 2002 ApJS, 141, 267                        Detachment
                                                         velocity




• Redshifted BAL onset




                                   flu
                                         Continuum           Em.




                                         x
                                                     BAL
                                                             line
• Possible occasionally in
  a rotation dominated                   blue                            red
                                                     wavelength
  wind




 BALs need a rotating wind
 … like the BELs
                                                                     Fermilab Colloqium 29 October 2003

                         3. Polarization: BAL troughs
                        Ogle et al. 1999 ApJS, 125, 1; Ogle 1998 PhD thesis, CalTech

BAL troughs are highly polarized –
   scattered light off flattened structure
=> BALs are common. Universal?
Scattering solves other BAL problems:
   ionization, abundances, NH

Thomson thick: X-ray Fe-K, Compton hump
Hamann 1998 ApJ 500, 798; Telfer et al. 1998 ApJ 509, 132




  Is the BAL wind itself the
     scatterer?




                                                                                                     Ogle, PhD thesis, 1998
  Bi-cone model Predicts
     distribution of non-BAL
     quasar polarization

        Conical wind fits BALs well
                                                             Fermilab Colloqium 29 October 2003


                     3. Polarization: VBELR
                          Young et al. 1999 MNRAS 303, 227

              If BALs are cones, all quasars should have BAL gas
• Supported by observations:                                   MKN 509

• Emission lines twice as broad in
  polarized, non-variable light.
                                                     Polarized light
•  non-BAL quasars have
                                                           2 x width
  Thomson thick gas at large,
  BAL, velocities
• Don’t see in absorption because
  out of our line of sight
• Large scattering region                             total light
•   (but not too large, Smith et al. 2003
    MNRAS)
• with BAL velocities
         BAL velocity gas exists in non-BAL quasars
                                                                           Fermilab Colloqium 29 October 2003


           One last, crucial, complication
  Angles are wrong:
  BAL velocities too high: ~10,000 km s-1
  10 times narrow absorption lines
  Requires extreme cone opening angle.
  Simple solution: bend wind

    Predicts:
1. ‘detached BALs’*
= Lowest velocity where wind bends into
      our line of sight
                                                                                Detachment
= vertical velocity from disk                                                    velocity

2. ~10% covering factor
dr at r gives 6o divergence angle
                                                         flu
                                                               Continuum             Em.
                                                               x            BAL
radiation forces gas to diverge                                                      line
     Both previously unexplained
                                                                            wavelength
         *Could this be an ionization effect? Dv a IP?
                                                    Fermilab Colloqium 29 October 2003

        Quasar Atmospheres, Quasar Winds
                                   One geometry unites all the features
                       High ionization
                      Broad emission lines
                        Low ionization




85 deg: narrow
absorption lines


                   60 deg: broad
                   absorption lines

                                             20 deg: no absorption lines
                                          Fermilab Colloqium 29 October 2003


         Components of Quasar Atmospheres




                                                    Thompson
High ionization: e.g. CIV, OVI
                                                    thick BAL
Low ionization: e.g. MgII, Hb.
                                                    scatterer must
                                                    also make
                                                    Compton
       All atomic features now included             hump, Fe-K
                                                      Fermilab Colloqium 29 October 2003

                       Putting it all together
                information filters worked efficiently!

Accelerating bi-conical wind
BALs
Polarization                    hollow cone
                               no absorption lines



Thin quasi-vertical wind                                 Supermassive black hole
BELs
                                                                Accretion disk
WAs
NALs
                                                     X-ray/UV ionizing continuum


                                       Elvis M., 2000, ApJ, 545, 63
                                                             Fermilab Colloqium 29 October 2003

 Hokusai never saw a live Elephant
Not bad – not 100% right – but gets the idea




      Blind men and the elephant. Manga VIII Hokusai, Katsushika (1760-1849)



This picture of quasar atmospheres is probably in
    much the same state: needs physics bones
                                                                            Fermilab Colloqium 29 October 2003


              A Quasar Observational Paradigm
Disk Winds: tie together all the pieces of the
    quasar atmosphere
• Explains features not ‘built in’
                  BAL covering factor; detachment velocity, Hi ionization BEL blueshifts.

• Survived tests X-ray absorber outflow v, 2-phase UV/X-ray absorber, pressure balance
• Makes predictions High ionization BEL, X/UV absorber radii, thickness are equal
•   Creates a research program c.f. Lakatos 1980
•   Allows tractable physics exploration…
•   Work BACK to origin in accretion disk physics
•   Work OUT to impact on surroundings

Can begin to build a ‘low’ theory of quasar atmospheres
                                                                    Fermilab Colloqium 29 October 2003

             low theory: 2-phase equilibrium
                       Krolik, McKee & Tarter 1981, ApJ, 249, 422

                                           Krongold, Nicastro, Brickhouse, Elvis, Liedahl & Mathur, 2003
•Photoionized gas tends to have phases
• Not really new:
•Does not work for a static medium
•so abandoned…. a mistake!

•Works fine in a wind. dynamic
•Equilibrium determined solely by:
SED & ionization thresholds
•Should be similar from object to object
•No need to assume ‘clouds’
                                                                       Fermilab Colloqium 29 October 2003
new
         low theory: accretion disk physics, II
        Krongold et al. in preparation                   Krongold, Nicastro, Brickhouse, Elvis, Liedahl &
                                                                          Mathur, 2003




 •~106K phase depends critically
 on SED Nicastro 1999, Reynolds & Fabian 1995
 • Use absorber (T,x) to determine
 unseeable EUV SED
 -> Test models of accretion disk
      •inner edge      ill-defined- boundary condition
                                                            Reynolds & Fabian 1995 MNRAS 273 116



      •‘plunging region’ Krolik et al.
                                                                         Fermilab Colloqium 29 October 2003
 new
                 low theory: Why is the wind thin?
                                   Risaliti & Elvis 2003, ApJ submitted

    • Intermediate level 2D theory
    • Wind driven by UV absorption lines                                          Wind
           – c.f. O-star winds, CAK                                 Middle               wind escapes
           – ignore gas pressure
    • 3 Zones: Inner, Middle, Outer                                  No wind
    • 1. Inner: over-ionized
           – Only Compton scattering - insufficient       Inner:        density
           – shields gas further out from X-rays
             = Murray & Chiang `hitchhiking gas’          `failed
                                                          wind’
    • 2. Middle: UV absorption drives gas
       –  wind escapes                                                           Outer: wind
                                                                                  falls back
    • 3. Outer: shielded from UV, weak initial
      push from local disk radiation
       – wind falls back
                                                        •Note: L>LEdd quasars always have winds
weakness      Some BALs are L>LEdd winds                •See King & Pounds 2003 astro-ph/0305571
                                                        •Reeves et al … ;Chartas et al…
                                                   Princeton AGN Physics with the SDSS, 29 July 2003

        Looking Out: quasars as dust factories
                 Elvis, Marengo & Karovska, 2002 ApJ, 567, L107
• Outflowing BEL gas expands and cools adiabatically
• BEL adiabats track through dust formation zone of AGB stars
                                              Applies to Carbon-rich and Oxygen-rich grains
 Outflows rates ~10 Msol/yr at
    L~1047 erg/s                                      Oxygen rich dust
                                                      Carbon rich dust
      0.1 Msol/yr of dust                                            Cooling BEL
                                                                      Cooling BEL clouds
                                                                      clouds
     assuming dust/gas ratio of Long Period
        Variables

      >107Msol over 108 yr outburst
       lifetime
  Metallicity super-solar even in z=6
   BELs
    • High Z/Zsol should enhance
        dust production
    • Larger dust masses likely
                                      Princeton AGN Physics with the SDSS, 29 July 2003


 Looking Out: quasars & starbursts
             Elvis, King et al., in preparation

• Conventionally, starbursts fuel quasar outbursts
      • What if it is the other way around?

  All Quasars have winds
  Quasar wind outflow rates ~1 Msol/yr at L~1046 erg/s
       shocks on host galaxy ISM
           induces starburst
               Fuels AGN
                   Wind
      … cycle of AGN/starburst activity?
                                       Fermilab Colloqium 29 October 2003




Quasar Atmospheres, Quasar Winds
            Good Observational Paradigm:
          Quasar Atmospheres are dynamic
      Thin, rotating, funnel-shaped disk wind
               Low Theory beginnings:
                   2 phase medium
                  Line driven winds
                      Prospects:
   Use quasar atmospheres for accretion disk physics
                Dust creation at high z
            Quasar to Starburst causality
                                                             Fermilab Colloqium 29 October 2003
               Postscript: Imaging Quasars
      What we really want is to look at quasar atmospheres
                                             Elvis & Karovska, 2002 ApJ, 581, L67
  At low z sizes are ~0.1 mas
 Resolvable with planned ground
 interferometers
     VLT-I, Ohana
Ideal telescopes:
•Image the wind in space and velocity
•5 km-10 km IR 2mm interferometer at
‘Dome C’ in Antartica
•½-1km UV space interferometer
                                                              Sizes are implicit in:
= NASA ‘Stellar Imager’                                       Peterson et al. 1999 ApJL 520, 659.
                                                              Kaspi et al. 2001 ApJ 533, 631
Quasar community should push for
“Quasi-Stellar Imager”           SOLVE QUASAR ATMOSPHERES
                                        No more fancy indirect deductions!

								
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