English
Related papers

Related papers: Metallicity Effects in PDRs

200 papers

We study the scaling relations between gas-phase metallicity, stellar mass surface density ($\Sigma _*$), star formation rate surface density ($\Sigma _{SFR}$), and molecular gas surface density ($\Sigma_{H_2}$) in local star-forming…

The physical and chemical conditions in photodissociation regions (PDRs) are largely determined by the influence of far ultraviolet radiation. Far-UV photons can efficiently dissociate molecular hydrogen, a process that must be balanced at…

Astrophysics of Galaxies · Physics 2018-06-08 P. Castellanos , A. Candian , H. Andrews , A. G. G. M. Tielens

Photodissociation regions (PDRs) contain a large fraction of all of the interstellar matter in galaxies. Classical examples include the boundaries between ionized regions and molecular clouds in regions of massive star formation, marking…

Astrophysics of Galaxies · Physics 2015-07-01 D. J. Stock , M. G. Wolfire , E. Peeters , A. G. G. M. Tielens , B. Vandenbussche , C. Boersma , J. Cami

Recent studies have found higher galaxy metallicities in richer environments. It is not yet clear, however, whether metallicity-environment dependencies are merely an indirect consequence of environmentally dependent formation histories, or…

Astrophysics of Galaxies · Physics 2016-05-18 Shy Genel

Our understanding of physical processes in Photodissociation regions or Photon Dominated Regions (PDRs) largely depends on the ability of spectral synthesis codes to reproduce the observed infrared emission-line spectrum. In this paper, we…

Astrophysics · Physics 2009-11-13 N. P. Abel , P. A. M. van Hoof , G. Shaw , G. J. Ferland , T. Elwert

[abridged] The star formation rates (SFR) of low-metallicity galaxies depend sensitively on the gas metallicity, because metals are crucial to mediating the transition from intermediate-temperature atomic gas to cold molecular gas, a…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Mark R. Krumholz , Avishai Dekel

We use a sample of 43,690 galaxies selected from the Sloan Digital Sky Survey Data Release 4 to study the systematic effects of specific star formation rate (SSFR) and galaxy size (as measured by the half light radius, r_h) on the…

Astrophysics · Physics 2009-11-13 Sara L. Ellison , David R. Patton , Luc Simard , Alan W. McConnachie

A possible relation between the high dispersion in metallicity of metal-poor halo stars and the minor merger processes in the history of the Galaxy is presented. The foreign populations of stars in the satellites through minor merger…

Astrophysics · Physics 2007-05-23 Y. Lu , K. S. Cheng , L. C. Deng

A number of previous studies have searched for a correlation between radial metallicity gradients and early-type galaxy mass -- no convincing trends have been found. Here we re-examine this issue with several key enhancements: using total…

Astrophysics · Physics 2009-11-11 Duncan A. Forbes , Patricia Sanchez-Blazquez , Robert Proctor

The question how much star formation is occurring at low metallicity throughout the cosmic history appears crucial for the discussion of the origin of various energetic transients, and possibly - double black hole mergers. We revisit the…

Astrophysics of Galaxies · Physics 2021-10-04 Martyna Chruslinska , Gijs Nelemans , Lumen Boco , Andrea Lapi

We have performed a series of calculations designed to reproduce infrared diagnostics used to determine physical conditions in star forming regions. We self-consistently calculate the thermal and chemical structure of an H II region and…

Astrophysics · Physics 2009-11-11 N. P. Abel , G. J. Ferland , G. Shaw , P. A. M. van Hoof

More complete knowledge of galaxy evolution requires understanding the process of star formation and interaction between the interstellar radiation field and the interstellar medium in galactic environments traversing a wide range of…

The relation between metallicity and galaxy mass (the so-called mass-metallicity relation) is the strongest and most prominent among scaling relations between chemical enrichment and galactic properties. However, it is unclear whether this…

Astrophysics of Galaxies · Physics 2025-12-17 Maria Koller , Roberto Maiolino , William M. Baker

The formation of planets within a disc must operate within the time frame of disc dispersal, it is thus crucial to establish what is the dominant process that disperses the gaseous component of discs around young stars. Planet formation…

Earth and Planetary Astrophysics · Physics 2015-05-14 Barbara Ercolano , Cathie Clarke

The effect of dust attenuation on a galaxy's light depends on a number of physical properties, such as geometry and dust composition, both of which can vary across the faces of galaxies. To investigate this variation, we continue analysis…

Metallicity is a key parameter that controls many aspects in the formation and evolution of stars and galaxies. In this review we focus on the metal deficient galaxies, in particular the most metal-poor ones, because they play a crucial…

Astrophysics · Physics 2009-11-19 D. Kunth , G. Ostlin

We have compared the metallicity (represented by oxygen abundance), and the dust-to-gas ratio, in a sample of dwarf galaxies. For dwarf irregulars (dIrrs) we find a good correlation between the two quantities, with a power-law index…

Astrophysics · Physics 2009-08-21 U. Lisenfeld , A. Ferrara

The dependence of gas giant planet occurrence rate on stellar metallicity has been firmly established. We extend this so-called planet-metallicity correlation to broader ranges of metallicities and planet masses/radii. In particular, we…

Earth and Planetary Astrophysics · Physics 2016-12-14 Wei Zhu , Ji Wang , Chelsea Huang

We investigate the metallicity dependence of HI surface densities in star-forming regions along many lines of sight within 70 nearby galaxies, probing kpc to 50 pc scales. We employ HI, SFR, stellar mass, and metallicity (gradient)…

Astrophysics of Galaxies · Physics 2018-08-08 Andreas Schruba , Shmuel Bialy , Amiel Sternberg

Presence of dust in galaxies removes half or more of the stellar energy from the UV-optical budget of the Universe and has profound impact on our understanding of how galaxies evolve. Measures of opacity in local galaxies are reviewed…

Astrophysics · Physics 2008-11-26 Daniela Calzetti