Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.naic.edu/~astro/chicago2/talks/Narayanan-CO_Emissionin_high-z_QSOs.pdf Дата изменения: Tue Aug 22 00:13:39 2006 Дата индексирования: Sun Dec 23 00:56:27 2007 Кодировка: Поисковые слова: п п п п п п п п п п п п п

The Nature of CO Emission in z>6 Quasars

Desika Narayanan
University of Arizona

Radiative Transfer Modeling
Chris Walker Romeel DavИ Craig Kulesa

Cosmological/Hydro Modeling
T.J. Cox Yuexing Li Lars Hernquist Sukanya Chakrabarti Tiziana Di Matteo Liang Gao Philip Hopkins Brant Robertson Volker Springel


Introduction: z>6 Quasars
· <1 Gyr after Big Bang

·

Host Galaxies allow us to study first collapsed objects

·

CO Observations probe molecular ISM and let us study coeval evolution of SMBH + Starburst

Desika Narayanan, Tucson Workshop August 3rd, 2006


J1148+5251 Primer
Global Properties
· · · · z=6.42 1014 L MBH=109 M SFR ~ 3000 M /yr
Barth et al., Bertoldi et al, Fan et al.

Molecular ISM Properties
· · Flux Density Peak J=6 2 component CO morphology (merger?) Lines observed at 3-2,6-5,7-6
Walter et al., Bertoldi et al.

·

Desika Narayanan, Tucson Workshop August 3rd, 2006


J1148+5251 Primer
Global Properties
· z=6.42


Molecular ISM Properties
· Flux Density Peak J=6

Goals0of L · 1 14 study: · 2 component CO 1. Provide a physical model for z>6 qso formation morphology (merger?) 2. Assess viability of model by · Lines observed at comparing to CO 3-2,6-5,7-6 · observations /yr SFR ~ 3000 M
Barth et al., Walter et observations 3. Facilitate Bertoldi et al, interpretation of existing COal., Bertoldi et al. Fan et al.

·

MBH=109 M

4. Make predictions for future z>6 CO observations of qsos/starbursts, and necessary technical requirements
Desika Narayanan, Tucson Workshop August 3rd, 2006


z>6 Quasar Formation Simulations
Cosmological, Hydro Simulations · Structure Formation models to identify most massive halo Resimulate most massive halo (1015M at z=0) to derive merger tree Hydrodynamically simulate galaxy mergers
­ Formulation for AGN feeback and starburst winds

Non-LTE Radiative Transfer · · Monte Carlo Code Subgrid formalism for mass spectrum of GMCs Passed standard published tests
Narayanan et al.(2006a,b)

·

· ·

·

7 major mergers z=14.4-8.5
Li et al (2006), Springel et al. (2005)

Desika Narayanan, Tucson Workshop August 3rd, 2006


z>6 Quasar Formation Simulations: 8 Galaxies Merging

QuickTimeTM and a YUV420 codec decompressor are needed to see this picture.

Desika Narayanan, Tucson Workshop August 3rd, 2006

Li et al (2006)


Simulated CO (J=1-0) Morphology

Narayanan et al.(2006)

Desika Narayanan, Tucson Workshop August 3rd, 2006


CO (J=3-2) Morphology
Simulations Observations (VLA)

Walter et al. (2004)

Narayanan et al.(2006)

Desika Narayanan, Tucson Workshop August 3rd, 2006


CO Excitation: CO SEDs
Simulations Observations

Bertoldi et al. 2004

J=6 Peak

Narayanan et al.(2006)

Bertoldi et al.(2004)

Desika Narayanan, Tucson Workshop August 3rd, 2006


CO (J=6-5) Emission Line Profiles
Simulations Observations

~2500 km/s FWHM

~280 km/s FWHM

Narayanan et al.(2006)

Bertoldi et al.; Walter et al

Large virial velocities in massive halo (~1000 km/s) cause large CO line widths

Desika Narayanan, Tucson Workshop August 3rd, 2006


CO (J=6-5) Emission Line Profiles
Simulations Observations

~2500 km/s FWHM

~280 km/s FWHM

Narayanan et al.(2006)

Bertoldi et al. 2004

Large virial velocities in massive halo (~1000 km/s) ~300 km/s cause similarly large CO line widths

FWHM

Desika Narayanan, Tucson Workshop August 3rd, 2006


Implications and Conclusions
Physical
· Line widths predicted to be large (2400-2600 km/s) Full line width observations necessary to measure true gas mass and constrain formation models. Merger Driven model for J1148+5251 may be viable ·

Technical Requirements
Large Bandwidth (~6000 km/s at 50 km/s resolution) spectrometers necessary for future generations of cm/mmwave receivers (EVLA) High spatial resolution (0.050.1") necessary to capture dynamics of possible high-z mergers (EVLA, ALMA) Higher frequency (~45 GHz) capability desirable

·

·

·

·

Desika Narayanan, Tucson Workshop August 3rd, 2006