On the Optimization of Broadband Photometry for Galaxy Evolution Studies

Paz, A. Gil de; Madore, Barry F.

doi:10.1086/339480

Cited by 27 publications

(24 citation statements)

References 49 publications

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“…These are key questions in galaxy evolution studies especially for the planning of galaxy surveys and observational proposals and for understanding the reliability of the results. In order to answer these questions we carry out a comprehensive test of various filter setups and their performance in recovering the galaxy physical properties (see also Gil de Paz & Madore 2002 for a similar study at low redshift using BC03‐type stellar population models). M06 discuss the importance of including the rest‐frame near‐IR in the fitting (illustrated in their fig.…”

Section: Spectral Energy Distribution Fittingmentioning

confidence: 99%

Recovering galaxy stellar population properties from broad-band spectral energy distribution fitting

Pforr¹,

Maraston²,

Tonini³

2012

Monthly Notices of the Royal Astronomical Society

227

296

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We explore the dependence of galaxy stellar population properties that are derived from broad‐band spectral energy distribution fitting – such as age, stellar mass, dust reddening, etc. – on a variety of parameters, such as star formation histories, age grid, metallicity, initial mass function (IMF), dust reddening and reddening law, filter setup and wavelength coverage. Mock galaxies are used as test particles. We confirm our earlier results based on real z= 2 galaxies, that usually adopted τ‐models lead to overestimate the star formation rate and to underestimate the stellar mass. Here, we show that – for star‐forming galaxies – galaxy ages, masses and reddening can be well determined simultaneously only when the correct star formation history is identified. This is the case for inverted‐τ models at high‐z, for which we find that the mass recovery (at fixed IMF) is as good as ∼0.04 dex. However, since the right star formation history is usually unknown, we quantify the offsets generated by adopting standard fitting setups. Stellar masses are generally underestimated, which results from underestimating the age. For mixed fitting setups with a variety of star formation histories the median mass recovery at z∼ 2–3 is as decent as ∼0.1 dex (at fixed IMF), albeit with large scatter. The situation worsens towards lower redshifts, because of the variety of possible star formation histories and ages. At z∼ 0.5 the stellar mass can be underestimated by as much as ∼0.6 dex (at fixed IMF). A practical trick to improve upon this figure is to exclude reddening from the fitting parameters, as this helps to avoid unrealistically young and dusty solutions. Stellar masses are underestimated by a smaller amount (∼0.3 dex at z∼ 0.5). Reddening and the star formation rate should then be determined via a separate fitting. As expected, the recovery of properties is better for passive galaxies, for which e.g. the mass can be fully recovered (within ∼0.01 dex at fixed IMF) when using a fitting setup including metallicity effects. In both cases of star‐forming as well as passive galaxies, the recovery of physical parameters is dependent on the spectral range involved in the fitting. We find that a coverage from the rest‐frame ultraviolet to the rest‐frame near‐infrared appears to be optimal. We also quantify the effect of narrowing the wavelength coverage or adding and removing filter bands, which can be useful for planning observational surveys. Finally, we provide scaling relations that allow the transformation of stellar masses obtained using different template fitting setups and stellar population models.

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Section: Spectral Energy Distribution Fittingmentioning

confidence: 99%

Recovering galaxy stellar population properties from broad-band spectral energy distribution fitting

Pforr¹,

Maraston²,

Tonini³

2012

Monthly Notices of the Royal Astronomical Society

227

296

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“…The solutions, however, are still degenerate since various combinations of , E(BϪV ) ranging from 0 to 0.5 mag, and extinction laws (LMC, SMC, and C94) all produce a low residual fit to the data. Since the timescales for the burst and underlying components in the models are now fixed, we find that the dominant source of degeneracy is the age-extinction degeneracy (Gil de Paz & Madore 2002). This is in the sense that an older burst with less dust extinction may yield as good a fit to the data as a younger but more extincted burst.…”

Section: Stellar Mass Estimatesmentioning

confidence: 90%

“…The blue end corresponds to a rest frame of ∼0.18 mm and of ∼0.23 mm, respectively. Gil de Paz & Madore (2002) have shown that this filter combination is well suited for deriving physical properties of galaxies at from broadband z ∼ 0.7 data alone, including the star formation timescale, age, metallicity, and stellar mass.…”

Section: Stellar Mass Estimatesmentioning

confidence: 99%

Stellar Masses of Luminous Compact Blue Galaxies at Redshifts [CLC][ITAL]z[/ITAL][/CLC] = 0.4–1.2

Guzmán

Östlin

Kunth

et al. 2003

The Astrophysical Journal

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We present stellar mass measurements for a sample of 36 luminous compact blue galaxies (LCBGs) at redshifts in the flanking fields around the Hubble Deep Field-North. The technique is based on fitting a twoz p 0.4-1.2 component galaxy population model to multi-broadband photometry. Best-fit models are found to be largely independent of the assumed values for the initial mass function (IMF) and the metallicity of the stellar populations, but they are sensitive to the amount of extinction and the extinction law adopted. On average, the best-fit model corresponds to a LMC extinction law with . Stellar mass estimates, however, are remarkably E(BϪV ) p 0.5 independent of the final model choice. Using a Salpeter IMF, the derived median stellar mass for this sample is M , i.e., ∼2 times smaller than previous virial mass estimates. Despite uncertainties of a factor of 2-3, 9 5 # 10 , our results strengthen prior claims that L* CBGs at intermediate redshifts are, on average, about 10 times less massive than a typical L* galaxy today.

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“…In spite of the wealth of optical spectroscopic information currently available thanks to recent large-area surveys (mainly the 2dFGRS and the SDSS), SEDs still provide invaluable and complementary information. It is well known (e.g., Thuan 1985;Gil de Paz & Madore 2002) that for nearby galaxies NIR photometry can sensitively constrain the age, metallicity, and mass of stellar populations -but the situation is more complex in the case of strongly star-forming galaxies (see Noeske et al 2003). Alternatively, UV data provide information on the amounts of dust, the age and mass, and the star formation rate of galaxies on a broader time scale than traced by Hα emission.…”

Section: Imaging and Spectroscopic Datamentioning

confidence: 99%

“…Furthermore, it has been shown that the UV emission provides reliable SFRs for galaxies with weak or non-existing Hα emission, and that the latter increasingly underpredicts the FUV-derived SFRs for low-mass galaxies (Lee et al 2009a). Additionally, for a fixed number of photometric points, wider wavelength baselines can significantly reduce the uncertainties in the derived parameters (Gil de Paz & Madore 2002). Finally, the analysis of SEDs is not restricted to objects with SDSS spectra, and thus allows for a direct comparison with dwarfs at higher redshifts, where spectroscopic data are scarce, but multiwavelength imaging is abundant.…”

Section: Imaging and Spectroscopic Datamentioning

confidence: 99%

A Virtual Observatory Census to Address Dwarfs Origins (AVOCADO)

Sánchéz-Janssen¹,

Amorín²,

García-Vargas³

et al. 2013

A&A

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Context. Even though they are by far the most abundant of all galaxy types, the detailed properties of dwarf galaxies are still only poorly characterised -especially because of the observational challenge that their intrinsic faintness and weak clustering properties represent. Aims. AVOCADO aims at establishing firm conclusions on the formation and evolution of dwarf galaxies by constructing and analysing a homogeneous, multiwavelength dataset for a statistically significant sample of approximately 6500 nearby dwarfs (M i − 5 log h 100 > −18 mag). The sample is selected to lie within the 20 < D < 60 h −1 100 Mpc volume covered by the SDSS-DR7 footprint, and is thus volume-limited for M i − 5 log h 100 < −16 mag dwarfs -but includes ≈1500 fainter systems. We will investigate the roles of mass and environment in determining the current properties of the different dwarf morphological types -including their structure, their star formation activity, their chemical enrichment history, and a breakdown of their stellar, dust, and gas content. Methods. We present the sample selection criteria and describe the suite of analysis tools, some of them developed in the framework of the Virtual Observatory. We use optical spectra and UV-to-NIR imaging of the dwarf sample to derive star formation rates, stellar masses, ages, and metallicities -which are supplemented with structural parameters that are used to classify them morphologically. This unique dataset, coupled with a detailed characterisation of each dwarf's environment, allows for a fully comprehensive investigation of their origins and enables us to track the (potential) evolutionary paths between the different dwarf types. Results. We characterise the local environment of all dwarfs in our sample, paying special attention to trends with current star formation activity. We find that virtually all quiescent dwarfs are located in the vicinity (projected distances 1.5 h −1 100 Mpc) of L * companions, consistent with recent results. While star-forming dwarfs are preferentially found at separations of the order of 1 h −1 100 Mpc, there appears to be a tail towards low separations ( 100 h −1 100 kpc) in the distribution of projected distances. We speculate that, modulo projection effects, this probably represents a genuine population of late-type dwarfs caught upon first infall about their host and before environmental quenching has fully operated. In this context, these results suggest that internal mechanisms -such as gas exhaustion via star formation or feedback effects -are not sufficient to completely cease the star formation activity in dwarf galaxies, and that becoming the satellite of a massive central galaxy appears to be a necessary condition to create a quiescent dwarf.

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On the Optimization of Broadband Photometry for Galaxy Evolution Studies

Cited by 27 publications

References 49 publications

Recovering galaxy stellar population properties from broad-band spectral energy distribution fitting

Recovering galaxy stellar population properties from broad-band spectral energy distribution fitting

Stellar Masses of Luminous Compact Blue Galaxies at Redshifts [CLC][ITAL]z[/ITAL][/CLC] = 0.4–1.2

A Virtual Observatory Census to Address Dwarfs Origins (AVOCADO)

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