On the impact of spectral template uncertainties in synthetic stellar populations

Byrne, Conor M.; Stanway, Elizabeth R.

doi:10.1093/mnras/stad832

Cited by 4 publications

(1 citation statement)

References 92 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…IFSFIT first masks emission lines, fits a continuum model, and then fits the resulting continuum-subtracted emission-line spectrum. We use ppxf (Cappellari 2012(Cappellari , 2017 to fit the stellar continua using the C3K theoretical stellar libraries at solar metallicity (Choi et al 2016;Byrne & Stanway 2023). We allow for stellar attenuation in ppxf.…”

Section: Spectramentioning

confidence: 99%

The Intrinsic Sizes of Odd Radio Circles

Rupke,

Coil,

Whalen

et al. 2024

ApJ

View full text Add to dashboard Cite

A new class of sources, the so-called odd radio circles (ORCs), have been discovered by recent sensitive, large-area radio continuum surveys. The distances of these sources have so far relied on photometric redshifts of optical galaxies found at the centers of or near ORCs. Here we present Gemini rest-frame optical spectroscopy of six galaxies at the centers of, or potentially associated with, the first five ORC discoveries. We supplement this with Legacy Survey imaging and Prospector fits to their griz+W1/W2 photometry. Of the three ORCs with central galaxies, all lie at distances (z = 0.27–0.55) that confirm the large intrinsic diameters of the radio circles (300–500 kpc). The central galaxies are massive (M * ∼ 1011 M ☉), red, unobscured ellipticals with old (≳1 Gyr) stellar populations. They have LINER spectral types that are shock-powered or active galactic nucleus (AGN)-powered. All three host low-luminosity, radio-quiet AGN. The similarity of their central galaxies is consistent with a common origin, perhaps as a blast wave from an ancient starburst. The other two ORCs are adjacent and have no prominent central galaxies. However, the z = 0.25 disk galaxy that lies between them hosts a Type 2, moderate-luminosity AGN. They may instead be the lobes of a radio jet from this AGN.

show abstract

Section: Spectramentioning

confidence: 99%

The Intrinsic Sizes of Odd Radio Circles

Rupke,

Coil,

Whalen

et al. 2024

ApJ

View full text Add to dashboard Cite

show abstract

The importance of stochasticity in determining galaxy emissivities and UV LFs during cosmic dawn and reionization

Nikolić,

Mesinger,

Davies

et al. 2024

A&A

View full text Add to dashboard Cite

The stochastic nature of star formation and photon propagation in high-redshift galaxies can result in sizable galaxy-to-galaxy scatter in their properties. Ignoring this scatter by assuming mean quantities can bias estimates of their emissivity and corresponding observables. We constructed a flexible, semi-empirical model, sampling scatter around the following mean relations: (i) the conditional halo mass function (CHMF); (ii) the stellar-to-halo mass relation (SHMR); (iii) the galaxy star formation main sequence (SFMS); (iv) the fundamental metallicity relation (FMR); (v) the conditional intrinsic luminosity; and (vi) the photon escape fraction. In our fiducial model, ignoring scatter in these galaxy properties overestimates the duration of the Epoch of Reionization (EoR), delaying its completion by $ z 1--2. We quantified the relative importance of each of the above sources of scatter in determining the ionizing, soft-band X-ray, and Lyman Werner (LW) emissivities as a function of scale and redshift. We find that scatter around the SFMS is important for all bands, especially at the highest redshifts where the emissivity is dominated by the faintest, most "bursty" galaxies. Ignoring this scatter would underestimate the mean emissivity and its standard deviation computed over 5 cMpc regions by factors of up to sim 2--10 at $5 z 15$. The scatter around the X-ray luminosity to star formation rate and metallicity relation is important for determining X-ray emissivity, accounting for roughly half of its mean and standard deviation. The importance of scatter in the ionizing escape fraction depends on its functional form, while scatter around the SHMR contributes at the level of sim 10--20<!PCT!>. Other sources of scatter have a negligible contribution to the emissivities. Although scatter does flatten the UV luminosity functions, shifting the bright end by 1--2 magnitudes, the level of scatter in our fiducial model is insufficient to fully explain recent estimates from JWST photometry (consistent with previous studies). We conclude that models of the EoR should account for the burstiness of star formation, while models for the cosmic 21cm signal should additionally account for scatter in intrinsic X-ray production.

show abstract

First Light and Reionization Epoch Simulations (flares) – XIV. The Balmer/4000 Å breaks of distant galaxies

Wilkins,

Lovell,

Irodotou

et al. 2023

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

With the successful launch and commissioning of JWST we are now able to routinely spectroscopically probe the rest-frame optical emission of galaxies at z > 6 for the first time. Among the most useful spectral diagnostics used in the optical is the Balmer/4000 Å break; this is, in principle, a diagnostic of the mean ages of composite stellar populations. However, the Balmer break is also sensitive to the shape of the star formation history, the stellar (and gas) metallicity, the presence of nebular continuum emission, and dust attenuation. In this work, we explore the origin of the Balmer/4000 Å break using the synthesizer synthetic observations package. We then make predictions of the Balmer/4000 Å break using the First Light and Reionization Epoch Simulations at 5 < z < 10. We find that the average break strength weakly correlates with stellar mass and rest-frame far-ultraviolet luminosity, but that this is predominantly driven by dust attenuation. We also find that break strength provides a weak diagnostic of the age but performs better as a means to constrain star formation and stellar mass, alongside the ultraviolet and optical luminosity, respectively.

show abstract

On the impact of spectral template uncertainties in synthetic stellar populations

Cited by 4 publications

References 92 publications

The Intrinsic Sizes of Odd Radio Circles

The Intrinsic Sizes of Odd Radio Circles

The importance of stochasticity in determining galaxy emissivities and UV LFs during cosmic dawn and reionization

First Light and Reionization Epoch Simulations (flares) – XIV. The Balmer/4000 Å breaks of distant galaxies

Contact Info

Product

Resources

About