Model-Independent Inference of Galaxy Star Formation Histories in the Local Volume

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F25%3A10509923" target="_blank" >RIV/00216208:11320/25:10509923 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=JadDvoTmUG" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=JadDvoTmUG</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3390/universe11100352" target="_blank" >10.3390/universe11100352</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Model-Independent Inference of Galaxy Star Formation Histories in the Local Volume

Popis výsledku v původním jazyce

Understanding the diversity of star formation histories (SFHs) of galaxies is key to reconstructing their evolutionary paths. Traditional models often assume parametric forms such as delayed-tau or exponentially declining models, which may not reflect the actual variety of formation processes. We aim to assess what types of SFHs are consistent with the observed present-day star formation rates (SFR0) and time-averaged star formation rates (&lt; SFR &gt;) of galaxies in the Local Volume, without assuming any fixed functional form. We construct a non-parametric framework by generating large ensembles of randomized SFHs for each galaxy in the sample. For each SFH, we compute its predicted stellar mass and present-day SFR and retain only those consistent with the observed values within a 20% tolerance. We then infer the statistical distribution of power-law slopes eta (fitted as SFR(t)proportional to(t-t(start))(eta)) and 50% stellar mass formation times t50. Across the full sample of 555 galaxies, we find that approximate to 70% have flat SFHs (|eta|&lt;= 0.01), approximate to 24% are mildly declining (eta&lt;-0.01), and approximate to 6% are rising (eta&gt;0.01). In the low-mass bin (M star&lt;3x10(9)M(circle dot)), rising SFHs slightly increase (approximate to 7%) but remain a minority as the majority have flat SFHs. Both eta and t50 correlate strongly with the SFR ratio (Spearman rho&gt;0.75, p &lt;&lt; 10(-16)), indicating that the shape and timing of star formation are primarily governed by this ratio. The t(50) distribution shows sharp spikes near 7.74 and 7.86 Gyr, which we attribute to grid discretization combined with filtering, rather than a physical bimodality. Our results confirm that strongly declining SFH templates are disfavored in the Local Volume: most systems are consistent with flat long-term SFHs, with only mild decline or occasional rising. Importantly, this is demonstrated through a fully model-independent, data-driven approach, with per-galaxy uncertainties quantified using the standard error of eta and t50 from the ensemble of accepted SFHs.

Název v anglickém jazyce

Model-Independent Inference of Galaxy Star Formation Histories in the Local Volume

Popis výsledku anglicky

Understanding the diversity of star formation histories (SFHs) of galaxies is key to reconstructing their evolutionary paths. Traditional models often assume parametric forms such as delayed-tau or exponentially declining models, which may not reflect the actual variety of formation processes. We aim to assess what types of SFHs are consistent with the observed present-day star formation rates (SFR0) and time-averaged star formation rates (&lt; SFR &gt;) of galaxies in the Local Volume, without assuming any fixed functional form. We construct a non-parametric framework by generating large ensembles of randomized SFHs for each galaxy in the sample. For each SFH, we compute its predicted stellar mass and present-day SFR and retain only those consistent with the observed values within a 20% tolerance. We then infer the statistical distribution of power-law slopes eta (fitted as SFR(t)proportional to(t-t(start))(eta)) and 50% stellar mass formation times t50. Across the full sample of 555 galaxies, we find that approximate to 70% have flat SFHs (|eta|&lt;= 0.01), approximate to 24% are mildly declining (eta&lt;-0.01), and approximate to 6% are rising (eta&gt;0.01). In the low-mass bin (M star&lt;3x10(9)M(circle dot)), rising SFHs slightly increase (approximate to 7%) but remain a minority as the majority have flat SFHs. Both eta and t50 correlate strongly with the SFR ratio (Spearman rho&gt;0.75, p &lt;&lt; 10(-16)), indicating that the shape and timing of star formation are primarily governed by this ratio. The t(50) distribution shows sharp spikes near 7.74 and 7.86 Gyr, which we attribute to grid discretization combined with filtering, rather than a physical bimodality. Our results confirm that strongly declining SFH templates are disfavored in the Local Volume: most systems are consistent with flat long-term SFHs, with only mild decline or occasional rising. Importantly, this is demonstrated through a fully model-independent, data-driven approach, with per-galaxy uncertainties quantified using the standard error of eta and t50 from the ensemble of accepted SFHs.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10308 - Astronomy (including astrophysics,space science)

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2025

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Universe

ISSN

2218-1997

e-ISSN

2218-1997

Svazek periodika

11

Číslo periodika v rámci svazku

10

Stát vydavatele periodika

CH - Švýcarská konfederace

Počet stran výsledku

18

Strana od-do

352

Kód UT WoS článku

001604497700001

EID výsledku v databázi Scopus

2-s2.0-105020076504