Spectral Energy Distributions for 258 Local Volume Galaxies

Abstract

We present model spectral energy distribution (SED) fits to ultraviolet/optical/infrared observations for the 258 nearby galaxies in the Local Volume Legacy survey, a sample dominated by lower-luminosity dwarf irregular systems. The data for each galaxy include up to 26 spatially-integrated broadband and narrowband fluxes from the Galaxy Evolution Explorer, Spitzer Space Telescope, and Infrared Astronomical Satellite space-based platforms, and from the Sloan Digital Sky Survey, Two Micron All Sky Survey, and other ground-based efforts. The CIGALE SED fitting package is employed using a delayed star-formation history with an optional late burst or quenching episode to constrain 11 different free parameters that characterize the properties of each galaxy’s stellar and dust emission, with the overriding constraint that the ultraviolet/optical emission absorbed by interstellar dust grains is emitted in equal energy portions at infrared wavelengths. The main results are: (i) 94% of the SED fits yield reduced χ 2 values less than 3; (ii) the modeled stellar masses agree with those derived from 3.6 μm-based measures with a scatter of 0.07 dex; (iii) for a typical galaxy in the sample the SED-derived star-formation rate averaged over the past 100 Myr is about 88% of the value derived from standard hybrid indicators on similar timescales; and (iv) there is a statistically significant inverse relation between the stellar mass fraction appearing in the late burst and the total stellar mass. These results build upon prior SED modeling efforts in the local volume and lay the groundwork for future studies of more distant low-metallicity galaxies with JWST.

Dwarf–Dwarf Interactions Can Both Trigger and Quench Star Formation

“…Here, the filled square symbols show the UV-based SFRs of UGC 5205 and PGC 027864, while the filled circle (in the case of PGC 027864) and the unfilled triangle (for UGC 5205) show the Hα-based SFR and upper limit, respectively. Here, one may immediately notice that although the UV-based SFR estimates of UGC 5205 and PGC 027864 place both galaxies on the starforming main sequence (SFMS) as defined by Dale et al (2023), there has been a marked divergence in star formation behavior between the ∼100 Myr timescales probed by the UV Note. The optical properties of UGC 5205 and galaxies within two projected virial radii of UGC 5205.…”

“…Figure 8 shows a comparison of our Hα-and UV-based SFR estimates, along with a local comparison sample of Local Volume Legacy galaxies (Dale et al 2023). Here, the filled square symbols show the UV-based SFRs of UGC 5205 and PGC 027864, while the filled circle (in the case of PGC 027864) and the unfilled triangle (for UGC 5205) show the Hα-based SFR and upper limit, respectively.…”

“…Figure 8. The placement of UGC 5205 and PGC 027864 relative to the lowmass SFMS as measured from UV-optical-IR spectral energy distribution (SED) fits of Dale et al (2023). The square symbols show UV-based SFR estimates, while the round circle and unfilled triangle show the Hα-based SFR estimate of PGC 027864 and the Hα upper limit estimate of UGC 5205, respectively.…”

The high energy X-ray probe: resolved X-ray populations in extragalactic environments

“…In somewhat more distant galaxies (e.g., up to ≈10 Mpc), there are several spiral and dwarf galaxies covering broad ranges of star-formation history and metallicity, and many comprehensive panchromatic surveys of these galaxy samples have been conducted to provide subgalactic properties of the sources (e.g., Kennicutt et al, 2003;Dalcanton et al, 2009;Calzetti et al, 2015;Lee et al, 2022;Dale et al, 2023). Within the volume of D < 10 Mpc, there are 7 galaxies with SFR above 5 M ⊙ yr −1 and 15 galaxies with SFR between 1 and 5 M ⊙ yr −1 .…”