The evolution of Galactic planetary nebula progenitors through the comparison of their nebular abundances with AGB yields

Ventura, P.; Stanghellini, Letizia; Dell’Agli, F.; García-Hernández, D. A.

doi:10.1093/mnras/stx1907

Cited by 30 publications

(36 citation statements)

References 64 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Low-and intermediate-mass (LIM) stars, with mass in the range 4 m 8M , are dominant stellar nucleosynthesis sources of N, when experiencing the AGB phase (see, for example, Ventura et al 2013Ventura et al , 2017 for more details). Most of the nitrogen from AGB stars is secondary and its stellar yields steadily increase as functions of the initial stellar metallicity.…”

Section: Chemical Enrichment Modelmentioning

confidence: 99%

Evolution of N/O ratios in galaxies from cosmological hydrodynamical simulations

Vincenzo

2018

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

We study the redshift evolution of the gas-phase O/H and N/O abundances, both (i) for individual ISM regions within single spatially-resolved galaxies and (ii) when dealing with average abundances in the whole ISM of many unresolved galaxies. We make use of a cosmological hydrodynamical simulation including detailed chemical enrichment, which properly takes into account the variety of different stellar nucleosynthetic sources of O and N in galaxies. We identify 33 galaxies in the simulation, lying within dark matter halos with virial mass in the range 10 11 M DM 10 13 M and reconstruct how they evolved with redshift. For the local and global measurements, the observed increasing trend of N/O at high O/H can be explained, respectively, (i) as the consequence of metallicity gradients which have settled in the galaxy interstellar medium, where the innermost galactic regions have the highest O/H abundances and the highest N/O ratios, and (ii) as the consequence of an underlying average mass-metallicity relation that galaxies obey as they evolve across cosmic epochs, where -at any redshift -less massive galaxies have lower average O/H and N/O ratios than the more massive ones. We do not find a strong dependence on the environment. For both local and global relations, the predicted N/O-O/H relation is due to the mostly secondary origin of N in stars. We also predict that the O/H and N/O gradients in the galaxy interstellar medium gradually flatten as functions of redshift, with the average N/O ratios being strictly coupled with the galaxy star formation history. Because N production strongly depends on O abundances, we obtain a universal relation for the N/O-O/H abundance diagram whether we consider average abundances of many unresolved galaxies put together or many abundance measurements within a single spatially-resolved galaxy.

show abstract

Section: Chemical Enrichment Modelmentioning

confidence: 99%

Evolution of N/O ratios in galaxies from cosmological hydrodynamical simulations

Vincenzo

2018

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

show abstract

“…However, nitrogen enhancement alone cannot be the solution of the NH 3 abundance problem. Hot bottom burning (HBB) in intermediate-mass AGB stars (M = 4-8 M ) can enhance the surface nitrogen abundance at the end of the AGB evolution by up to an order of magnitude (Karakas & Lattanzio 2014;Ventura et al 2017). In massive stars (M 8 M ), nitrogen is primarily produced in the CN branch of the CNO cycles (Henry et al 2000) and the surface nitrogen abundance in A-type supergiants could increase by a factor of a few (< 10) compared to the solar value due to partial mixing of the CNcycled gas (Venn 1995).…”

Section: Ammonia Chemistrymentioning

confidence: 99%

Circumstellar ammonia in oxygen-rich evolved stars

Wong

Menten

Kamiński

et al. 2018

A&A

View full text Add to dashboard Cite

Context. The circumstellar ammonia (NH 3 ) chemistry in evolved stars is poorly understood. Previous observations and modelling showed that NH 3 abundance in oxygen-rich stars is several orders of magnitude above that predicted by equilibrium chemistry. Aims. We would like to characterise the spatial distribution and excitation of NH 3 in the oxygen-rich circumstellar envelopes (CSEs) of four diverse targets: IK Tau, VY CMa, OH 231.8+4.2, and IRC +10420. Methods. We observed NH 3 emission from the ground state in the inversion transitions near 1.3 cm with the Very Large Array (VLA) and submillimetre rotational transitions with the Heterodyne Instrument for the Far-Infrared (HIFI) aboard Herschel Space Observatory from all four targets. For IK Tau and VY CMa, we observed NH 3 rovibrational absorption lines in the ν 2 band near 10.5 µm with the Texas Echelon Cross Echelle Spectrograph (TEXES) at the NASA Infrared Telescope Facility (IRTF). We also attempted to search for the rotational transition within the excited vibrational state ( 2 = 1) near 2 mm with the IRAM 30m Telescope. Non-LTE radiative transfer modelling, including radiative pumping to the vibrational state, was carried out to derive the radial distribution of NH 3 in the CSEs of these targets. Results. We detected NH 3 inversion and rotational emission in all four targets. IK Tau and VY CMa show blueshifted absorption in the rovibrational spectra. We did not detect vibrationally excited rotational transition from IK Tau. Spatially resolved VLA images of IK Tau and IRC +10420 show clumpy emission structures; unresolved images of VY CMa and OH 231.8+4.2 indicate that the spatial-kinematic distribution of NH 3 is similar to that of assorted molecules, such as SO and SO 2 , that exhibit localised and clumpy emission. Our modelling shows that the NH 3 abundance relative to molecular hydrogen is generally of the order of 10 −7 , which is a few times lower than previous estimates that were made without considering radiative pumping and is at least 10 times higher than that in the carbon-rich CSE of IRC +10216. NH 3 in OH 231.8+4.2 and IRC +10420 is found to emit in gas denser than the ambient medium. Incidentally, we also derived a new period of IK Tau from its V-band light curve. Conclusions. NH 3 is again detected in very high abundance in evolved stars, especially the oxygen-rich ones. Its emission mainly arises from localised spatial-kinematic structures that are probably denser than the ambient gas. Circumstellar shocks in the accelerated wind may contribute to the production of NH 3 . Future mid-infrared spectroscopy and radio imaging studies are necessary to constrain the radii and physical conditions of the formation regions of NH 3 .

show abstract

“…Recent surveys such as SDSS DR12 using 100000 star forming galaxies (Masters et al 2016) or SDSS IV MaNGA using 550 nearby galaxies (Belfiore et al 2017) show an interesting correlation between the N/O ratio and the stellar mass of these galaxies which could be more fundamental than the relation N/O vs O/H at a redshift around 0. Finally note that N abundances have been measured in planetary nebulae and these studies can be used to test AGB stellar models (Stanghellini et al 2006;Stanghellini & Haywood 2010;Cavichia et al 2017;Ventura et al 2017) at different metallicities/masses.…”

Section: Datamentioning

confidence: 99%

Cosmological evolution of the nitrogen abundance

Vangioni

Dvorkin

Olive

et al. 2018

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

The abundance of nitrogen in the interstellar medium is a powerful probe of star formation processes over cosmological timescales. Since nitrogen can be produced both in massive and intermediate-mass stars with metallicity-dependent yields, its evolution is challenging to model, as evidenced by the differences between theoretical predictions and observations. In this work we attempt to identify the sources of these discrepancies using a cosmic evolution model. To further complicate matters, there is considerable dispersion in the abundances from observations of damped Lyα absorbers (DLAs) at z ∼ 2 − 3. We study the evolution of nitrogen with a detailed cosmic chemical evolution model and find good agreement with these observations, including the relative abundances of (N/O) and (N/Si). We find that the principal contribution of nitrogen comes from intermediate mass stars, with the exception of systems with the lowest N/H, where nitrogen production might possibly be dominated by massive stars. This last result could be strengthened if stellar rotation which is important at low metallicity can produce significant amounts of nitrogen. Moreover, these systems likely reside in host galaxies with stellar masses below 10 8.5 M ⊙ . We also study the origin of the observed dispersion in nitrogen abundances using the cosmological hydrodynamical simulations Horizon-AGN. We conclude that this dispersion can originate from two effects: difference in the masses of the DLA host galaxies, and difference in the their position inside the galaxy.

show abstract

The evolution of Galactic planetary nebula progenitors through the comparison of their nebular abundances with AGB yields

Cited by 30 publications

References 64 publications

Evolution of N/O ratios in galaxies from cosmological hydrodynamical simulations

Evolution of N/O ratios in galaxies from cosmological hydrodynamical simulations

Circumstellar ammonia in oxygen-rich evolved stars

Cosmological evolution of the nitrogen abundance

Contact Info

Product

Resources

About