FUV and X-Ray Absorption in the Warm-Hot Intergalactic Medium

Richter, Philipp; Paerels, F.; Kaastra, J. S.

doi:10.1007/s11214-008-9325-4

Cited by 46 publications

(19 citation statements)

References 85 publications

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“…This characterization of the WHIM is more observationally oriented. Indeed, different distributions of metallicity determine what are the best tracers (chemical elements and their ionization states) to reveal the presence of the WHIM and characterize its physical properties: the presence of different ionization species, that are thought to be the best WHIM tracers, depends in fact upon local conditions of density, temperature and ionization field (see Richter et al 2008, for a review).…”

Section: Resultsmentioning

confidence: 99%

The impact of feedback on the low-redshift intergalactic medium

Tornatore

Borgani

Viel

et al. 2010

Monthly Notices of the Royal Astronomical Society

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We analyse the evolution of the properties of the low‐redshift intergalactic medium (IGM) using high‐resolution hydrodynamic simulations that include a detailed chemical evolution model. We focus on the effects that two different forms of energy feedback, strong galactic winds driven by supernova explosion and active galactic nuclei powered by gas accretion on to super‐massive black holes (BHs), have on the thermo‐ and chemodynamical properties of the low‐redshift IGM. We find that feedback associated with winds (W) and BHs leaves distinct signatures in both the chemical and thermal history of the baryons, especially at redshift z < 3. BH feedback produces an amount of gas with temperature in the range of 105–107 K, the warm‐hot intergalactic medium (WHIM), larger than that produced by the wind feedback. At z= 0, the fraction of baryons in the WHIM is about 50 per cent in the runs with BH feedback and about 40 per cent in the runs with wind feedback. The number of warm baryons (104 < T < 105 K) is instead at about the same level, ∼30 per cent, in the runs with BH and wind feedback. Also, BH feedback provides a stronger and more pristine enrichment of the WHIM. We find that the metal‐mass‐weighted age of WHIM enrichment at z= 0 is on average a factor of ∼1.5 smaller in the BH run than for the corresponding runs with galactic winds. We present results for the enrichment in terms of mass and metallicity distributions for the WHIM phase, both as a function of density and as a function of temperature. Finally, we compute the evolution of the relative abundances between different heavy elements, namely oxygen, carbon and iron. While both C/O and O/Fe evolve differently at high redshifts for different feedback models, their values are similar at z= 0. We also find that changing the stellar initial mass function has a smaller effect on the evolution of the above relative abundances than changing the feedback model. The sensitivity of WHIM properties on the implemented feedback scheme could be important both for discriminating between different feedback physics and for detecting the WHIM with future far‐UV and X‐ray telescopes.

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Section: Resultsmentioning

confidence: 99%

The impact of feedback on the low-redshift intergalactic medium

Tornatore

Borgani

Viel

et al. 2010

Monthly Notices of the Royal Astronomical Society

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“…Nevertheless, the literature is rich in attempts to model the distributions of the hot gas density (which because of the high degree of ionization refers uniquely to electron density) in different environments e.g. in the LG (Rasmussen & Pedersen 2001;Binney & Evans 2001;Maloney & Bland-Hawthorn 1999) by considering different constraints, in clusters of galaxies by fitting the X-ray observations with β -models (e.g., Cavaliere & Fusco-Femiano 1976) and by fitting the MW hot coronal gas (e.g., Moore & Davis 1994;Fukugita & Peebles 2006;Richter et al 2008;Savage et al 2003;Tumlinson & Fang 2005). In a hierarchical galaxy formation scenario, after the initial collapse, the continuing accretion of gas-rich fragments can produce a diffuse hot gas halo that surrounds the galaxies and fills the dark matter potential (White & Rees 1978;White & Frenk 1991), but not necessarily with the same radial profiles (Fukugita & Peebles 2006).…”

Section: Galaxy Model and Plasma Distributionmentioning

confidence: 99%

Dissipative phenomena in extended-body interactions

Pasetto

Bertelli

Grebel

et al. 2012

A&A

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Aims. Dissipative phenomena occurring during the orbital evolution of a dwarf satellite galaxy around a host galaxy may leave signatures in the star formation activity and signatures in the colour-magnitude diagram of the galaxy stellar content. Our goal is to reach a simple and qualitative description of these complicated phenomena. Methods. We develop an analytical and numerical technique able to study the ram pressure, Kelvin-Helmholtz instability, RayleighTaylor, and tidal forces acting on the star formation processes in molecular clouds. We consider it with synthetic colour-magnitude diagram techniques. Results. We developed a method of investigating the connections between gas consumption processes and star formation processes in the context of the two extended-body interactions, paying special attention to the dwarf galaxies dynamical regime.

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“…O vii and O viii have transitions accessible to X‐ray instruments, as does O vi . Searches for such absorbers have been hampered by the relatively poor resolution of modern X‐ray instruments and the small number of sources observable at high enough S/N by the Chandra and XMM–Newton observatories (see recent summaries by Bregman 2007 and Richter, Paerels & Kaastra 2008). While a number of measurements have been presented in the literature (e.g.…”

Section: Introductionmentioning

confidence: 99%

Strong z ∼ 0.5 O vi absorption towards PKS 0405−123: implications for ionization and metallicity of the Cosmic Web^★

Howk¹,

Ribaudo²,

Lehner³

et al. 2009

Monthly Notices of the Royal Astronomical Society

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We present observations of the intervening O vi absorption‐line system at zabs= 0.495 096 towards the quasi‐stellar object (QSO) PKS 0405−123 (zem= 0.5726) obtained with the Far Ultraviolet Spectroscopic Explorer and Space Telescope Imaging Spectrograph on board the Hubble Space Telescope. In addition to strong O vi, with , and moderate H i, with , this absorber shows absorption from C iii, N iv, O iv and O v, with upper limits for another seven ions. The large number of available ions allows us to test ionization models usually adopted with far fewer constraints. We find that the observed ionic column densities cannot be matched by single‐temperature collisional ionization models, in or out of equilibrium. Photoionization models can match all of the observed column densities, including O vi. If one assumes photoionization by an ultraviolet (UV) background dominated by QSOs, the metallicity of the gas is [O/H]≈−0.15, while if one assumes a model for the UV background with contributions from ionizing photons escaping from galaxies the metallicity is [O/H]≈−0.62. Both give [N/O]∼−0.6 and [C/H]∼−0.2 to ∼−0.1, though a solar C/O ratio is not ruled out. The choice of ionizing spectrum is poorly constrained and leads to systematic abundance uncertainties of ≈0.5 dex, despite the wide range of available ions. Multiphase models with a contribution from both photoionized gas (at T∼ 104 K) and collisionally ionized gas [at T∼ (1−3) × 105 K] can also match the observations for either assumed UV background giving very similar metallicities. We do not detect Ne viii or Mg x absorption. The limit on Ne viii/O vi< 0.21 (3σ) is the lowest yet observed. Thus, this absorber shows no firm evidence of the ‘warm‐hot intergalactic medium’ at T∼ (0.5–3) × 106 K thought to contain a significant fraction of the baryons at low redshift. The O vi in this system is not necessarily a reliable tracer of the warm‐hot intergalactic medium given the ambiguity in its origins. We present limits on the total column of warm‐hot gas in this absorber as a function of temperature. This system would be unlikely to provide detectable X‐ray absorption in the ions O vii or O viii even if it resided in front of the brighter X‐ray sources in the sky.

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FUV and X-Ray Absorption in the Warm-Hot Intergalactic Medium

Cited by 46 publications

References 85 publications

The impact of feedback on the low-redshift intergalactic medium

The impact of feedback on the low-redshift intergalactic medium

Dissipative phenomena in extended-body interactions

Strong z ∼ 0.5 O vi absorption towards PKS 0405−123: implications for ionization and metallicity of the Cosmic Web^★

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FUV and X-Ray Absorption in the Warm-Hot Intergalactic Medium

Cited by 46 publications

References 85 publications

The impact of feedback on the low-redshift intergalactic medium

The impact of feedback on the low-redshift intergalactic medium

Dissipative phenomena in extended-body interactions

Strong z ∼ 0.5 O vi absorption towards PKS 0405−123: implications for ionization and metallicity of the Cosmic Web★

Contact Info

Product

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Strong z ∼ 0.5 O vi absorption towards PKS 0405−123: implications for ionization and metallicity of the Cosmic Web^★