Submillimetre and far-infrared spectral energy distributions of galaxies: the luminosity-temperature relation and consequences for photometric redshifts

By A. Blain, V. Barnard, S. Chapman. 2002

161 citations recorded by the source corpus.

The spectral energy distributions (SEDs) of dusty high-redshift galaxies are poorly sampled in frequency and spatially unresolved. Their form is crucially important for estimating the large luminosities of these galaxies accurately, for providing circumstantial evidence concerning their power sources, and for estimating their redshifts in the absence of spectroscopic information. We discuss the suite of parameters necessary to describe their SEDs adequately without introducing unnecessary complexity. We compare directly four popular descriptions, explain the key degeneracies between the parameters in each when confronted with data, and highlight the differences in their best-fitting values. Using one representative SED model, we show that fitting to even a large number of radio, submillimetre and far-infrared (far-IR) continuum colours provides almost no power to discriminate between the redshift and dust temperature of an observed galaxy, unless an accurate relationship with a tight scatter exists between luminosity and temperature for the whole galaxy population. We review our knowledge of this luminosity–dust temperature relation derived from three galaxy samples, to better understand the size of these uncertainties. Contrary to recent claims, we stress that far-IR-based photometric redshifts are unlikely to be sufficiently accurate to impose useful constraints on models of galaxy evolution: finding spectroscopic redshifts for distant dusty galaxies will remain essential.

Subfields: Astronomy and Astrophysics, Electrical and Electronic Engineering, Instrumentation

View Paper: https://www.semanticscholar.org/paper/66d0ca08415e629c601a57641fd63865c110a232

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. D. M. Alexander
2. P. Hopkins
3. L. Hernquist
4. D. Narayanan
5. F. Walter
6. C. Casey
7. E. Daddi
8. D. Elbaz

In Electrical and Electronic Engineering

1. C. Casey
2. S. Chapman
3. R. Ivison
4. C. Carilli
5. F. Walter
6. A. Blain
7. Bruce G. Elmegreen
8. D. Narayanan

In Instrumentation

1. D. M. Alexander
2. E. Daddi
3. D. Narayanan
4. P. Hopkins
5. L. Hernquist
6. D. Elbaz
7. C. Casey
8. R. Genzel

Citations in the corpus

• Dusty Star Forming Galaxies at High Redshift (2014, result): “−α (Blain et al., 2003; Younger et al., 2007, 2009b; Roseboom et al., 2013).”
• Planck 2013 results. XI. All-sky model of thermal dust emission (2013, background): “It has been shown by many authors (Blain et al. 2003; Schnee et al. 2007; Shetty et al. 2009b; Kelly et al. 2012; Juvela & Ysard 2012a,b; Ysard et al. 2012) that, in general, the values of Tobs and βobs recovered from an MBB fit cannot be related simply to the mass-weighted average along the line…”
• Far-infrared spectral energy distribution fitting for galaxies near and far (2012, methodology): “Note that another popular infrared SED fitting method joins a greybody to a mid-infrared powerlaw using a piecewise technique (Blain et al. 2002, 2003), where the transition point between greybody and powerlaw is defined by d/dλ (S)=α, i.e. the gradients are equal.”
• SHARC-2 350 μm Observations of Distant Submillimeter-selected Galaxies (2006, methodology): “If power-law Wien tails, with spectral slopes of (Blain et al. 2003), are assumed instead, the luminosities can be scaled by a constant ( ), which is around 1.5 for an Arp 220 type template with ¼ 2.”
• RECONSTRUCTING THE STELLAR MASS DISTRIBUTIONS OF GALAXIES USING S4G IRAC 3.6 AND 4.5 μm IMAGES. I. CORRECTING FOR CONTAMINATION BY POLYCYCLIC AROMATIC HYDROCARBONS, HOT DUST, AND INTERMEDIATE-AGE STARS (2011, methodology): “Using the measured ratio Fs2,3.6/F8,ns we find a spectral index consistent with n=2 (Blain et al. 2003; as expected for power-law emission on the Wien side of the dust spectrum) with which we recover the observed flux at 24µm within 15%, on average, in both NGC 1566 and NGC 3031.”
• Characterization of Scuba-2 450 μm and 850 μm selected galaxies in the COSMOS field (2013, methodology): “The emissivity index, β = 1.5 is fixed (e.g. Pope et al. 2008; Younger et al. 2009; Chapin et al. 2010), as is the midinfrared powerlaw index, α = 2.0 (e.g. Blain et al. 2003; Casey 2012).”
• OBSERVATIONS OF Arp 220 USING HERSCHEL-SPIRE: AN UNPRECEDENTED VIEW OF THE MOLECULAR GAS IN AN EXTREME STAR FORMATION ENVIRONMENT (2011, background): “Multiple studies have shown that dust SEDs for ULIRGs may not only be fit by a single temperature optically-thick dust component but also by multiple optically-thin (assuming τdust << 1) temperature components, with both models fitting the SED equally well (Klaas et al. 2001; Blain et al. 2003).”
• Building the cosmic infrared background brick by brick with Herschel/PEP. ⋆ (2011, background): “One common source of discrepancy seems to be the well-know degeneracy between dust temperature (and hence luminosity and total dust mass)and redshift (e.g. Blain et al. 2003): red objects can be either cool local galaxies or warmer distant galaxies.”
• Planck 2013 results. XXX. Cosmic infrared background measurements and implications for star formation (2013, unknown): “A very simple functional form (see Blain et al. 2003, and reference therein) is assumed for galaxy SEDs: Θ(ν, z) ∝ { νβBν (Td(z)) ν < ν0 ; ν−γ ν ≥ ν0.”
• A Herschel view of the far-infrared properties of submillimetre galaxies (2012, methodology): “Despite its simplicity and the fact that it is known that this model cannot fully reproduce the Wien side of the far-infrared SED of galaxies (e.g., Blain et al. 2003; Magnelli et al. 2010; Hwang et al. 2010), we adopted this model for two reasons: (i) studies of theInfrared Astronomical…”
• KILOPARSEC-SCALE DUST DISKS IN HIGH-REDSHIFT LUMINOUS SUBMILLIMETER GALAXIES (2016, background): “…and gas surface densities Infrared–luminous galaxies in the local (e.g., Chapin et al. 2009; Hwang et al. 2010) and high–redshift universe (e.g., Blain et al. 2003; Chapman et al. 2003a) have long been known to show a relation between their dust temperatures and infrared luminosities (the…”
• Highly-excited CO emission in APM 08279+5255 at z = 3.9 (2007, unknown): “They correspond to the “starburst” and “AGN” components respectively, in similar fits to the dust spectrum by Rowan-Robinson (2000) and Beelen et al. (2006; see also the multi-component fits to APM 08279 by Blain et al. 2003).”
• Outflows in Infrared-Luminous Starbursts at z < 0.5. I. Sample, Na I D Spectra, and Profile Fitting (2005, methodology): “For many of these sources, infrared luminosities were calculated by including radio fluxes in the SED fitting and using the radio/infrared correlation (Blain et al. 2003; A. Blain 2003, private communication).”
• 350 μm Dust Emission from High-Redshift Quasars (2006, background): “For most objects, only two photometric data points (S1 and S2 at 1 and 2) are available, resulting in a degeneracy between the dust temperature and (Priddey & McMahon 2001; Blain et al. 2003): eh 1=kTdust eh 2=kTdust ¼ 1; ð3Þ where ¼ 2/ 1ð Þ3þ S1/S2.”
• SWIRE: The SIRTF Wide‐Area Infrared Extragalactic Survey (2001, background): “Rowan-Robinson (2001) suggests that the high redshift IR population might be dominated by cooler dust emission from larger disks than the sub-kpc-scale warm dust sources that seem to characterize local ULIRGs, and indeed Chapman et al. (2003a) find evidence for some cool ISO sources at z∼1.”