SED templates (Daniel Dale)

Infrared SED Templates for Galaxies
Daniel Dale
University of Wyoming
NGC 0628 @ 70,100,170um
Leiden NGC 0925 @ 70,100,170um
Herschel and the Characteristics of Dust in Galaxies
NGC 6946 @ 70,100,170um
04 March 2011
Outline
Brief overview of popular infrared templates
How they differ
Recent results from Herschel
What is needed?
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
“Templates” vs “Grids”
For this presentation, the following definitions
are adopted:
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
“Templates” vs “Grids”
For this presentation, the following definitions
are adopted:
Templates ­ A collection of observed spectra or single­parameter models
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
“Templates” vs “Grids”
For this presentation, the following definitions
are adopted:
Templates ­ A collection of observed spectra or single­parameter models
Grids – multi­dimensional models
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
Some Popular Infrared SED “templates”
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
Some Popular Infrared SED “templates”
Parameterized by either shape (for multi­ surveys)
or by luminosity (e.g., cosmology surveys)
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
Some Popular Infrared SED “templates”
Parameterized by either shape (for multi­ surveys)
or by luminosity (e.g., cosmology surveys)
Existing bivariate infrared color­luminosity relation:
Chapman et al. 2003
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
Dale & Helou (2002)
Désert et al. (1990) framework: PAHs + VSGs + BGs, for each 0.3<U<103 Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
Dale & Helou (2002)
Désert et al. (1990) framework: PAHs + VSGs + BGs, for each 0.3<U<103 PAHs updated via ISO
VSGs given new temperature distribution profiles
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
Dale & Helou (2002)
Désert et al. (1990) framework: PAHs + VSGs + BGs, for each 0.3<U<103 PAHs updated via ISO
VSGs given new temperature distribution profiles
Far­IR updated via ISO/IRAS/SCUBA
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
Dale & Helou (2002)
Désert et al. (1990) framework: PAHs + VSGs + BGs, for each 0.3<U<103 PAHs updated via ISO
VSGs given new temperature distribution profiles
Far­IR updated via ISO/IRAS/SCUBA, e.g., (>200m) = 2.5­0.4logU Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
Dale & Helou (2002)
Désert et al. (1990) framework: PAHs + VSGs + BGs, for each 0.3<U<103 PAHs updated via ISO
VSGs given new temperature distribution profiles
Far­IR updated via ISO/IRAS/SCUBA, e.g., (>200m) = 2.5­0.4logU Variable power­law dist'n of radiation fields
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
Dale & Helou (2002)
Lacks Spitzer mid­IR updates
Extends only to LIRGs
“Single­parameter” family
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
Dale & Helou (2002)
Lacks Spitzer mid­IR updates
Extends only to LIRGs
“Single­parameter” family
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
Chary & Elbaz (2001)
Silva et al. 1998 models to create ULIRG,LIRG,SB,normal Arp220,N6090,M82,M51
1012 L⊙
1011 L⊙
1010 L⊙
sequence defined by infrared luminosity
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
Chary & Elbaz (2001)
Silva et al. 1998 models to create ULIRG,LIRG,SB,normal Arp220,N6090,M82,M51
3­18m replaced with ISO spectrum
1012 L⊙
1011 L⊙
1010 L⊙
sequence defined by infrared luminosity
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
Chary & Elbaz (2001)
Silva et al. 1998 models to create ULIRG,LIRG,SB,normal Arp220,N6090,M82,M51
3­18m replaced with ISO spectrum
Interpolated; added Dale et al. (2001) templates to increase variety
1012 L⊙
1011 L⊙
1010 L⊙
sequence defined by infrared luminosity
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
Chary & Elbaz (2001)
Silva et al. 1998 models to create ULIRG,LIRG,SB,normal Arp220,N6090,M82,M51
3­18m replaced with ISO spectrum
Interpolated; added Dale et al. (2001) templates to increase variety
1012 L⊙
1011 L⊙
1010 L⊙
sequence defined by infrared luminosity
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
Lagache et al. (2003)
Tweaked Désert et al. (1990) / Dale et al. (2001), to better fit galaxy number counts
3∙1012 L⊙
5∙1011 L⊙
1011 L⊙
1010 L⊙
sequence defined by infrared luminosity
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
Lagache et al. (2003)
Tweaked Désert et al. (1990) / Dale et al. (2001), to better fit galaxy number counts
3∙1012 L⊙
5∙1011 L⊙
1011 L⊙
1010 L⊙
sequence defined by infrared luminosity
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
Brandl et al. (2006)
Collection of 22 Spitzer mid­infrared spectra (starbust or starburst+AGN)
Span wide range in silicate absorption
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
Smith et al. (2007)
“Noise­free” mid­infrared spectra from SINGS/Spitzer
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
Rieke et al. (2009)
Empirical data for ULIRGs and LIRGs, including IRS spectra
Single T blackbody
Extends to lower LIR using Dale & Helou (2002) & Smith et al. (2007)
sequenced according to LIR
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
Rieke et al. (2009)
Empirical data for ULIRGs and LIRGs, including IRS spectra
Single T blackbody
Extends to lower LIR using Dale & Helou (2002) & Smith et al. (2007)
Stronger PAH at high L
than Chary & Elbaz
sequenced according to LIR
More peaked at high L
than Dale & Helou
Less cold dust emission
at low L and more Si
absorption at high L, than
Siebenmorgen & Krügel
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
Some Popular Infrared SED “grids”
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
Some Popular Infrared SED “grids”
The larger number of free parameters allow
for more sophisticated interpretations
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
Siebenmorgen & Krügel (2007)
Radiative transfer assuming spherical symmetry and no clumps
Tested with 7 galaxies
NSED=7000
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
Siebenmorgen & Krügel (2007)
Radiative transfer assuming spherical symmetry and no clumps
Tested with 7 galaxies
NSED=7000
Varies with:
Luminosity
Visual obscuration
Nuclear size
OB­to­total luminosity
Dust density in hot spots
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
da Cunha et al. (2008)
Balances the inferred stellar attenuation with dust output
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
da Cunha et al. (2008)
Balances the inferred stellar attenuation with dust output
Fitted components:
Age
SFR
Metallicity
Attenuation of old stars
Attenuation of young stars
PAHs
VSGs
Warm BGs
Cold BGs
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
Draine & Li (2007)
Physical dust models for PAHs, carbonaceous grains, & amorphous silicate grains
Heated by a power­law distribution of starlight intensities
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
Draine & Li (2007)
Physical dust models for PAHs, carbonaceous grains, & amorphous silicate grains
Heated by a power­law distribution of starlight intensities
Returns:
PAH mass fraction
Umin (and Umax)
Mdust PDR fraction  See also Zubko et al. 2004
Jonsson et al. 2010
Compiègne et al. 2010
Narayanan et al. 2010
...
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
Ideally the different templates should ...
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
… fit the observed range of SEDs
Leiden Kartaltepe et al. (2010)
Herschel and the Characteristics of Dust in Galaxies
04 March 2011
… fit the observed range of SEDs
Leiden Kartaltepe et al. (2010)
Herschel and the Characteristics of Dust in Galaxies
04 March 2011
Spoon et al. (2007)
… reflect full diversity in obscuration
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
Spoon et al. (2007)
… reflect full diversity in obscuration
Deeply obscured
Naked AGN
Leiden Pure SB
Herschel and the Characteristics of Dust in Galaxies
04 March 2011
Boselli et al. (2010)
… match the observed colors
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
Draine & Li (2007)
… be consistent in
quantities like TIR
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
… be consistent in monochromatic / bolometric comparisons
Barro et al. (2011)
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
… be flexible enough to accommodate evolution
Hwang et al. (2010)
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
… be flexible enough to accommodate evolution
Symeonidis et al. (2009)
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
New Results from Herschel
NGC 6946 @ 70,100,170um
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
Fitting Draine & Li (2007) curves
Power­law distribution over
radiation field intensities U
stellar
diffuse fraction 1­ for U = Umin ~ G0 PDR fraction  Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
Panchromatic SEDs
IRAC, ISOCAM, MIPS, IRAS, PACS, SPIRE, SCUBA
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
SED fit parameters
Aniano et al. 2010, in prep
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
SED parameters: The impact of Herschel
PDR fraction
post/pre Herschel ratios plotted
PAH mass fraction
minimum radiation field
Dust mass
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
Dust masses
How accurate are single T (modified) blackbody estimates?
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
Dust masses
How accurate are single T (modified) blackbody estimates?
They are about 50% of the mass estimated via Draine & Li (2007)
For BB fits restricted to 100­500m
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
What is needed?
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
What is needed?
Is there substantial cold dust in galaxies?
How does the dust emissivity behave at long ?
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
What is needed?
Is there substantial cold dust in galaxies?
How does the dust emissivity behave at long ?
→Large submm maps (>500m) of large galaxies
low­metallicity galaxies
galaxy peripheries
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
What is needed?
What does the dust continuum look like near 35m?
Draine & Li (2007)
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
What is needed?
What does the dust continuum look like near 35m?
→SOFIA observations at 37m
Draine & Li (2007)
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011
Thank you
Leiden Herschel and the Characteristics of Dust in Galaxies
04 March 2011