Dissecting Nearby Galaxies with piXedfit. I. Spatially Resolved Properties of Stars, Dust, and Gas as Revealed by Panchromatic SED Fitting

Abstract

We study spatially resolved properties (on spatial scales of ∼1–2 kpc out to at least 3 effective radii) of the stars, dust, and gas in 10 nearby spiral galaxies. The properties of the stellar population and dust are derived by fitting the spatially resolved spectral energy distribution (SED) with more than 20 photometric bands ranging from far-ultraviolet to far-infrared. Our newly developed software piXedfit performs point-spread function matching of images, pixel binning, and models the stellar light, dust attenuation, dust emission, and emission from a dusty torus heated by an active galactic nucleus simultaneously through the energy-balance approach. With this self-consistent analysis, we present the spatially resolved version of the IRX–β relation, finding that it is consistent with the relationship from the integrated photometry. We show that the old stellar populations contribute to the dust heating, which causes an overestimation of the star formation rate (SFR) derived from the total ultraviolet and infrared luminosities on kiloparsec scales. With archival high-resolution maps of atomic and molecular gas, we study the radial variation of the properties of the stellar populations (including stellar mass, age, metallicity, and SFR), dust (including dust mass, dust temperature, and abundance of polycyclic aromatic hydrocarbon), and gas, as well as dust-to-stellar mass and dust-to-gas mass ratios. We observe a depletion of the molecular gas mass fraction in the central region of the majority of the galaxies, suggesting that the lack of available fuel is an important factor in suppressing the specific SFR at the center.

Star Cluster Formation and Evolution in M101: An Investigation with the Legacy Extragalactic UV Survey

“…In fact, the color-magnitude-diagram data suggests the SFH in the C and NW regions of M101 has been roughly constant or even decreasing in the center over the last 300 Myr. These results are also consistent with a recent pixel-based panchromatic SED analysis of the SFH for 10 nearby galaxies, finding that the specific SFR and star formation efficiency are suppressed in the C region of M101 despite the increase in the fraction of molecular gas (Abdurro'uf et al 2022). Thus, we can reasonably interpret the steepness of the age distributions as reflective of the strength of cluster disruption mechanisms in that region.…”

Dissecting Nearby Galaxies with piXedfit. II. Spatially Resolved Scaling Relations among Stars, Dust, and Gas

“…We investigate the scaling relations on kiloparsec scales by exploiting high-resolution maps of the spatially resolved properties, including the surface densities of stars, SFR, dust, and the atomic and molecular gas, of ten nearby spiral galaxies that were obtained in Abdurro'uf et al (2022). The surface densities of stars (Σ * ), dust (Σ dust ), and SFR (Σ SFR ) were obtained by performing the spatially resolved SED fitting on FUV-FIR imaging data using the piXedfit software, while the surface densities of the atomic and molecular gas (Σ HI and S H 2 ) were obtained from the archival data.…”

Spatially Resolved Stellar Populations of 0.3 < z < 6.0 Galaxies in WHL 0137–08 and MACS 0647+70 Clusters as Revealed by JWST: How Do Galaxies Grow and Quench over Cosmic Time?

“…Abdurro'uf & Akiyama (2017) analyzed 93 spiral galaxies at 0.01 < z < 0.02 using imaging data from the GALEX (Morrissey et al 2007) and SDSS (York et al 2000) surveys. Abdurro'uf et al (2022a) applied PIXEDFIT for analyzing 10 nearby galaxies using imaging data in more than 20 filters spanning the far-ultraviolet (FUV) to FIR.…”