OH+and H2O+absorption toward PKS 1830–211

Müller, S.; Müller, H. S. P.; Black, J. H.; Beelen, A.; Combes, F.; Curran, S. J.; Gérin, M.; Guèlin, M.; Henkel, C.; Martín, S.; Aalto, S.; Falgarone, É.; Menten, K. M.; Schilke, P.; Wiklind, T.; Zwaan, M. A.

doi:10.1051/0004-6361/201629073

Cited by 45 publications

(24 citation statements)

References 54 publications

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“…The high cosmic-ray ionization rate of ζ ∼ 10 −15 s −1 is also found in a molecular cloud in the vicinity of the supernova remnant W51C (Ceccarelli et al 2011). High values of the cosmic-ray ionization rate of ζ = 2 × 10 −14 -3 × 10 −15 s −1 were found in two lines of sight in the z = 0.89 molecular absorber toward the quasar PKS1830-211 (Muller et al 2016).…”

Section: Derived Physical Parametersmentioning

confidence: 73%

Starburst Energy Feedback Seen through HCO⁺/HOC⁺ Emission in NGC 253 from ALCHEMI

Harada

Martín

Mangum

et al. 2021

ApJ

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Molecular abundances are sensitive to the UV photon flux and cosmic-ray ionization rate. In starburst environments, the effects of high-energy photons and particles are expected to be stronger. We examine these astrochemical signatures through multiple transitions of HCO+ and its metastable isomer HOC+ in the center of the starburst galaxy NGC 253 using data from the Atacama Large Millimeter/submillimeter Array large program ALMA Comprehensive High-resolution Extragalactic Molecular inventory. The distribution of the HOC+(1−0) integrated intensity shows its association with “superbubbles,” cavities created either by supernovae or expanding H ii regions. The observed HCO+/HOC+ abundance ratios are ∼10–150, and the fractional abundance of HOC+ relative to H2 is ∼1.5 × 10−11–6 × 10−10, which implies that the HOC+ abundance in the center of NGC 253 is significantly higher than in quiescent spiral arm dark clouds in the Galaxy and the Galactic center clouds. Comparison with chemical models implies either an interstellar radiation field of G 0 ≳ 103 if the maximum visual extinction is ≳5, or a cosmic-ray ionization rate of ζ ≳ 10−14 s−1 (3–4 orders of magnitude higher than that within clouds in the Galactic spiral arms) to reproduce the observed results. From the difference in formation routes of HOC+, we propose that a low-excitation line of HOC+ traces cosmic-ray dominated regions, while high-excitation lines trace photodissociation regions. Our results suggest that the interstellar medium in the center of NGC 253 is significantly affected by energy input from UV photons and cosmic rays, sources of energy feedback.

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Section: Derived Physical Parametersmentioning

confidence: 73%

Starburst Energy Feedback Seen through HCO⁺/HOC⁺ Emission in NGC 253 from ALCHEMI

Harada

Martín

Mangum

et al. 2021

ApJ

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“…Both molecules have been detected in a foreground absorber at z = 0.89 toward the lensed quasar PKS 1830−211. The absorber is thought to be Milky-Way-like, and the two lensed images of the quasar provide two different sight lines through the disc of this galaxy, in which ionisation rates of about 10 −15 s −1 and 10 −14 s −1 are inferred (Muller et al, 2016). Oxygen-bearing ions are now also being detected in lensed submillimetre bright galaxies at z > 2 by ALMA, and while high ionisation Fig.…”

Section: Extragalactic Studiesmentioning

confidence: 96%

Impact of Low-Energy Cosmic Rays on Star Formation

et al. 2020

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In recent years, exciting developments have taken place in the identification of the role of cosmic rays in star-forming environments. Observations from radio to infrared wavelengths and theoretical modelling have shown that lowenergy cosmic rays (< 1 TeV) play a fundamental role in shaping the chemical richness of the interstellar medium, determining the dynamical evolution of molecular clouds. In this review we summarise in a coherent picture the main results obtained by observations and by theoretical models of propagation and generation 2 Marco Padovani et al.of cosmic rays, from the smallest scales of protostars and circumstellar discs, to young stellar clusters, up to Galactic and extragalactic scales. We also discuss the new fields that will be explored in the near future thanks to new generation instruments, such as: CTA, for the γ-ray emission from high-mass protostars; SKA and precursors, for the synchrotron emission at different scales; and ELT/HIRES, JWST, and ARIEL, for the impact of CRs on exoplanetary atmospheres and habitability.

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“…The star formation rate (SFR, which can be linked to the number of supernova remnants using an initial mass function) of the Milky Way in the past therefore should influence the LIS in the past. For instance, high ionization rates (with large uncertainties) have been inferred for galaxies at high redshifts that have higher SFRs than the present-day Milky Way (Muller et al 2016;Indriolo et al 2018). In these studies, the inferred ionization rate is attributed to Galactic cosmic rays.…”

Section: Comparison Of Solar Stellar and Galactic Cosmic Ray Spectramentioning

confidence: 99%

Stellar versus Galactic: the intensity of cosmic rays at the evolving Earth and young exoplanets around Sun-like stars

Rodgers-Lee

Taylor²,

Vidotto

et al. 2021

Monthly Notices of the Royal Astronomical Society

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Energetic particles, such as stellar cosmic rays, produced at a heightened rate by active stars (like the young Sun) may have been important for the origin of life on Earth and other exoplanets. Here we compare, as a function of stellar rotation rate (Ω), contributions from two distinct populations of energetic particles: stellar cosmic rays accelerated by impulsive flare events and Galactic cosmic rays. We use a 1.5D stellar wind model combined with a spatially 1D cosmic ray transport model. We formulate the evolution of the stellar cosmic ray spectrum as a function of stellar rotation. The maximum stellar cosmic ray energy increases with increasing rotation i.e. towards more active/younger stars. We find that stellar cosmic rays dominate over Galactic cosmic rays in the habitable zone at the pion threshold energy for all stellar ages considered (t* = 0.6 − 2.9 Gyr). However, even at the youngest age, t* = 0.6 Gyr, we estimate that ≳ 80MeV stellar cosmic ray fluxes may still be transient in time. At ∼1 Gyr when life is thought to have emerged on Earth, we demonstrate that stellar cosmic rays dominate over Galactic cosmic rays up to ∼4 GeV energies during flare events. Our results for t* =0.6 Gyr (Ω = 4Ω⊙) indicate that ≲GeV stellar cosmic rays are advected from the star to 1 au and are impacted by adiabatic losses in this region. The properties of the inner solar wind, currently being investigated by the Parker Solar Probe and Solar Orbiter, are thus important for accurate calculations of stellar cosmic rays around young Sun-like stars.

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OH⁺and H₂O⁺absorption toward PKS 1830–211

Cited by 45 publications

References 54 publications

Starburst Energy Feedback Seen through HCO⁺/HOC⁺ Emission in NGC 253 from ALCHEMI

Starburst Energy Feedback Seen through HCO⁺/HOC⁺ Emission in NGC 253 from ALCHEMI

Impact of Low-Energy Cosmic Rays on Star Formation

Stellar versus Galactic: the intensity of cosmic rays at the evolving Earth and young exoplanets around Sun-like stars

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OH+and H2O+absorption toward PKS 1830–211

Cited by 45 publications

References 54 publications

Starburst Energy Feedback Seen through HCO+/HOC+ Emission in NGC 253 from ALCHEMI

Starburst Energy Feedback Seen through HCO+/HOC+ Emission in NGC 253 from ALCHEMI

Impact of Low-Energy Cosmic Rays on Star Formation

Stellar versus Galactic: the intensity of cosmic rays at the evolving Earth and young exoplanets around Sun-like stars

Contact Info

Product

Resources

About

OH⁺and H₂O⁺absorption toward PKS 1830–211

Starburst Energy Feedback Seen through HCO⁺/HOC⁺ Emission in NGC 253 from ALCHEMI

Starburst Energy Feedback Seen through HCO⁺/HOC⁺ Emission in NGC 253 from ALCHEMI