The chemical evolution of galaxies with a variable integrated galactic initial mass function

Recchi, Simone; Kroupa, Pavel

doi:10.1093/mnras/stu2338

Cited by 41 publications

(33 citation statements)

References 71 publications

(93 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this regard, it is interesting to note that their radial velocities have opposite signs, once the systemic motion of NGC 1052 is subtracted. Thus, they may both be ancient metal-poor tidal dwarf galaxies orbiting NGC 1052 (Recchi & Kroupa 2015). This is reminiscent of the results obtained by Ibata et al (2014).…”

Section: Discussionsupporting

confidence: 57%

A new formulation of the external field effect in MOND and numerical simulations of ultra-diffuse dwarf galaxies – application to NGC 1052-DF2 and NGC 1052-DF4

Haghi

Kroupa

Banik

et al. 2019

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

The ultra-diffuse dwarf galaxy NGC 1052-DF2 (DF2) has ten (eleven) measured globular clusters (GCs) with a line-of-sight velocity dispersion of σ = 7.8 +5.2 −2.2 km/s (σ = 10.6 +3.9 −2.3 km/s). Our conventional statistical analysis of the original ten GCs gives σ = 8.0 +4.3 −3.0 km/s. The overall distribution of velocities agrees well with a Gaussian of this width. Due to the non-linear Poisson equation in MOND, a dwarf galaxy has weaker self-gravity when in close proximity to a massive host. This external field effect is investigated using a new analytic formulation and fully self-consistent live N-body models in MOND. Our formulation agrees well with that of Famaey and McGaugh (2012). These new simulations confirm our analytic results and suggest that DF2 may be in a deep-freeze state unique to MOND. The correctly calculated MOND velocity dispersion agrees with our inferred dispersion and that of van Dokkum et al. (2018b) if DF2 is within 150 kpc of NGC 1052 and both are 20 Mpc away. The GCs of DF2 are however significantly brighter and larger than normal GCs, a problem which disappears if DF2 is significantly closer to us. A distance of 10-13 Mpc makes DF2 a normal dwarf galaxy even more consistent with MOND and the 13 Mpc distance reported by Trujillo et. al. (2019). We discuss the similar dwarf DF4, finding good agreement with MOND. We also discuss possible massive galaxies near DF2 and DF4 along with their distances and peculiar velocities, noting that NGC 1052 may lie at a distance near 10 Mpc.

show abstract

Section: Discussionsupporting

confidence: 57%

A new formulation of the external field effect in MOND and numerical simulations of ultra-diffuse dwarf galaxies – application to NGC 1052-DF2 and NGC 1052-DF4

Haghi

Kroupa

Banik

et al. 2019

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

show abstract

“…In our simulation, the metallicity dependence of the gwIMF leads to a feedback effect since a low-metallicity environment results in a more top-heavy gwIMF (Yan et al 2017, their Fig. B.1) leading to a higher IMF-weighted metal yield (Recchi & Kroupa 2015). This effect makes the final metallicity of the galaxy not sensitive to its initial value.…”

Section: Initial Gas Metallicitymentioning

confidence: 79%

Chemical evolution of elliptical galaxies with a variable IMF

Yan

Jeřabková

Kroupa

et al. 2019

A&A

View full text Add to dashboard Cite

Growing evidence in recent years suggests a systematic variation of the stellar initial mass function (IMF), being top-heavy for starburst galaxies and possibly bottom-heavy for massive ellipticals. Galaxy chemical evolution simulations adopting an invariant canonical IMF face difficulty in simultaneously reproducing the metallicity and α-enhancement of the massive elliptical galaxies. Applying a variable IMF that changes with time is a promising solution, however, it is non-trivial to couple a variable IMF theory with the existing galaxy evolution codes. Here we present the first open source simulation code which recalculates the galaxy-wide IMF at each time step according to the Integrated-Galactic-IMF (IGIMF) theory where the galaxy-wide IMF depends on the galactic star formation rate and metallicity. The resulting galaxy-wide IMF and metal abundance evolve with time. With this pilot work, we explore the effect of the IGIMF theory on galaxy chemical evolution in comparison with an invariant IMF.

show abstract

“…Zorotovic et al 2010;Toonen & Nelemans 2013;Camacho et al 2014;Cojocaru et al 2017) and constant star formation rate (e.g. Kroupa et al 2013;Recchi & Kroupa 2015;Schulz et al 2015) but the situation with respect to initial binary distributions is less clear.…”

Section: Discussionmentioning

confidence: 99%

No cataclysmic variables missing: higher merger rate brings into agreement observed and predicted space densities

Belloni

Schreiber

Zorotovic

et al. 2018

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

The predicted and observed space density of cataclysmic variables (CVs) have been for a long time discrepant by at least an order of magnitude. The standard model of CV evolution predicts that the vast majority of CVs should be period bouncers, whose space density has been recently measured to be ρ 2 × 10 −5 pc −3 . We performed population synthesis of CVs using an updated version of the Binary Stellar Evolution (BSE) code for single and binary star evolution. We find that the recently suggested empirical prescription of consequential angular momentum loss (CAML) brings into agreement predicted and observed space densities of CVs and period bouncers. To progress with our understanding of CV evolution it is crucial to understand the physical mechanism behind empirical CAML. Our changes to the BSE code are also provided in details, which will allow the community to accurately model mass transfer in interacting binaries in which degenerate objects accrete from low-mass main-sequence donor stars.

show abstract

The chemical evolution of galaxies with a variable integrated galactic initial mass function

Cited by 41 publications

References 71 publications

A new formulation of the external field effect in MOND and numerical simulations of ultra-diffuse dwarf galaxies – application to NGC 1052-DF2 and NGC 1052-DF4

A new formulation of the external field effect in MOND and numerical simulations of ultra-diffuse dwarf galaxies – application to NGC 1052-DF2 and NGC 1052-DF4

Chemical evolution of elliptical galaxies with a variable IMF

No cataclysmic variables missing: higher merger rate brings into agreement observed and predicted space densities

Contact Info

Product

Resources

About