Spectral Properties of Populations Behind the Coherence in Spitzer Near-infrared and Chandra X-Ray Backgrounds

Li, Yanxia; Cappelluti, N.; Hasinger, G.; Arendt, Richard G.; Kashlinsky, A.; Pacucci, Fabio

doi:10.3847/1538-4357/ab397c

Cited by 5 publications

(5 citation statements)

References 45 publications

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“…Similar fluctuations were discovered in the cosmic X-ray background (CXB) observed in a deep Chandra survey, which are correlated with the CIB anisotropies in the same field [22]. Later studies of wider/deeper fields covered by both Chandra and Spitzer [23][24][25] have substantially improved the detection significance of the observed signal. The X-ray fluctuations contribute about 20% to the CIB signal, indicating that black hole accretion should be responsible for such highly efficient X-ray emission.…”

Section: Introductionsupporting

confidence: 60%

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Illuminating the dark ages: Cosmic backgrounds from accretion onto primordial black hole dark matter

Hasinger

2020

Preprint

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The recent interpretation of cold dark matter as the sum of contributions of different mass Primordial Black Hole (PBH) families [1] could explain a number of so far unsolved mysteries, like e.g. the massive seed black holes required to create the supermassive black holes in the earliest QSOs, the ubiquitous massive LIGO/VIRGO massive binary black holes, or even the putative "Planet X" PBH in our Solar System. By far the most abundant family of PBH should be around the Chandrasekhar mass (1.4 M ). This prediction may already have been vindicated by the recent OGLE/GAIA discovery of a sizeable population of putative black holes in the mass range 1-10 M .Here I assume that all dark matter exists in the form of 1.4 M PBH and estimate the contribution of baryon accretion onto this population to various cosmic background radiations, concentrating first on the cross-correlation signal between the Cosmic X-ray and the Cosmic infrared background fluctuations discovered in deep Chandra and Spitzer surveys. I assume Bondi accretion with reasonable parameters like baryon density and the effective relative velocity between baryons and PBH as well as appropriate accretion and radiation efficiencies and integrate these over cosmic time. I indeed predict a contribution of PBH accretion to the X-ray background consistent with the residual X-ray fluctuation signal. This signal peaks at redshifts z≈17-30, consistent with other constraints requiring the signal to come from such high redshifts. The PBH contribution to the 2-5 µm Cosmic Infrared background fluctuations is only about 1%, so that these likely come from star formation processes in regions associated with the PBH.I discuss a number of other phenomena, which could be significantly affected by the PBH accretion. Magnetic fields are an essential ingredient in the Bondi accretion process, and argue that the PBH can play an important role in amplifying magnetic seed fields in the early universe and maintaining them until the galactic dynamo processes set in. Next I study the contribution of the assumed PBH population to the re-ionization history of the universe and find that they do not conflict with the stringent ionization limits set by the most recent Planck measurements. X-ray heating from the PBH population can provide a contribution to the entropy floor observed in groups of galaxies. The tantalizing redshifted 21-cm absorption line feature observed by em EDGES could be connected to the radio emission contributed by PBH to the cosmic background radiation. Finally, the diffuse X-ray emission in the Galactic Center region is not violated by the assumed PBH dark matter, on the contrary, some of the discrete sources resolved in the deepest Chandra observations of the Galactic Ridge could indeed be accreting PBH. Contents 1 Introduction 1 2 Basic parameters of the toy model 3 3 Accretion spectrum and radiative efficiency 6 4 The contribution of PBH to the extragalactic background light 8 5 Discussion 11 5.1 Linear versus post-linear growth 11 5.2 Magnetic fields in the early...

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Section: Introductionsupporting

confidence: 60%

“…These authors also ruled out local diffuse emission as the source of the X-ray fluctuations. The spectral shape of the CXB fluctuations determined from a combination of the deepest/widest fields [25] can be fit either with a very high redshift population of obscured black holes, or with completely unobscured black hole accretion.…”

Section: Introductionmentioning

confidence: 99%

Illuminating the dark ages: Cosmic backgrounds from accretion onto primordial black hole dark matter

Hasinger

2020

Preprint

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“…We should note here that from a statistical point of view and to compare the analysed metastable dark energy models in this paper with ΛCDM model, we do not expect that these models perform better than the standard ΛCDM model by estimating the Bayes factor (as done in Pan et al (2019), analysing the model proposed in Li & Shafieloo (2019)). The fact is that having an extra degree of freedom in these metastable models, we have not achieved a substantial improvements in the likelihood estimations (as shown in Table 2 , 3, 4).…”

Section: Discussionmentioning

confidence: 84%

“…Recent papers have also drawn attention to some other difficulties faced by ΛCDM including tension between the value of H 0 estimated by fitting to the acoustic peaks in the Planck CMB power spectrum (Collaboration et al 2014;Ade et al 2016;Aghanim et al 2018) and that obtained from distance scale estimates (Sahni et al 2014;Ding et al 2015;Zheng et al 2016;Solà et al 2017;Alam et al 2017b;Shanks et al 2018). In order to alleviate these problems, different solutions such as dark energy models beyond ΛCDM model, modifications to general relativity theory and other physically-motivated possibilities like modifications to the dark matter sector have been put forward (Ko et al 2017;Raveri et al 2017;Kumar & Nunes 2017;Di Valentino et al 2017;Renk et al 2017;Solà et al 2017;Di Valentino et al 2018;Khosravi et al 2019;Poulin et al 2019;Vattis et al 2019;Li & Shafieloo 2019;Pan et al 2019).…”

Section: Introductionmentioning

confidence: 99%

Revisiting Metastable Dark Energy and Tensions in the Estimation of Cosmological Parameters

Shafieloo

Sahni

et al. 2019

ApJ

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We investigate constraints on some key cosmological parameters by confronting metastable dark energy models with different combinations of the most recent cosmological observations. Along with the standard ΛCDM model, two phenomenological metastable dark energy models are considered: (i) DE decays exponentially, (ii) DE decays into dark matter. We find that: (1) when considering the most recent supernovae and BAO data, and assuming a fiducial ΛCDM model, the inconsistency in the estimated value of the Ω m,0 h 2 parameter obtained by either including or excluding Planck CMB data becomes very much substantial and points to a clear tension (Sahni et al. 2014; Zhao et al. 2017); (2) although the two metastable dark energy models that we study provide greater flexibility in fitting the data, and they indeed fit the SNe Ia+BAO data substantially better than ΛCDM, they are not able to alleviate this tension significantly when CMB data are included; (3) while local measurements of the Hubble constant are significantly higher relative to the estimated value of H 0 in our models (obtained by fitting to SNe Ia and BAO data), the situation seems to be rather complicated with hints of inconsistency among different observational data sets (CMB, SNe Ia+BAO and local H 0 measurements). Our results indicate that we might not be able to remove the current tensions among different cosmological observations by considering simple modifications of the standard model or by introducing minimal dark energy models. A complicated form of expansion history, different systematics in different data and/or a non-conventional model of the early Universe might be responsible for these tensions. stein et al. 2005;Komatsu et al. 2009). The simplest and best known candidate for dark energy is the cosmological constant Λ whose value remains unchanged as the Universe expands. While current observational data are in agreement with the standard ΛCDM cosmology, General Relativity (GR) with a cosmological constant, though being completely consistent intrinsically at the classical level and having no more problems than GR itself at the quantum level, faces some well-known theoretical difficulties, such as the "fine-tuning" and "cosmic coincidence" problems, when trying to relate the observed small and positive value of the cosmological constant to parameters of the Standard Model of elementary parti-

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“…The CC between XRB and cosmic infrared background (CIRB) has suggested presence of high-z direct collapse black holes (Li et al 2018b;Mitchell-Wynne et al 2016;Cappelluti et al 2013;Li et al 2019b) as a source of excess fluctuation in CIRB. The source is still controversial, and the CC with the 21 cm line and these background map might be an evidence for the high-z components.…”

Section: Cosmic Microwave Background Near Infraredmentioning

confidence: 99%

Exploring the cosmic dawn and epoch of reionization with 21cm line

Shimabukuro,

Hasegawa,

Kuchinomachi

et al. 2023

Preprint

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The dark age of the universe, when no luminous object had existed, ended with the birth of the first stars, galaxies, and blackholes. This epoch is called cosmic dawn. Cosmic reionization is the major transition of the intergalactic medium (IGM) in the universe driven by ionizing photons emitted from luminous objects. Although the epoch through the dark age to reionization is a milestone in the universe, our knowledge of this epoch has not been sufficient yet. Cosmic 21cm signal, which is emitted from neutral hydrogen, is expected to open a new window for this epoch. In this review paper, we first introduce the basic physics of the 21cm line and how first stars impact on the 21cm line signal. Next, we briefly summarize how we extract astrophysical information from the 21cm line signal by means of statistical and machine learning approaches. We also discuss the synergy between the 21cm line signal and other emission lines. Finally, we summarize the current status of 21cm experiments.

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Spectral Properties of Populations Behind the Coherence in Spitzer Near-infrared and Chandra X-Ray Backgrounds

Cited by 5 publications

References 45 publications

Illuminating the dark ages: Cosmic backgrounds from accretion onto primordial black hole dark matter

Illuminating the dark ages: Cosmic backgrounds from accretion onto primordial black hole dark matter

Revisiting Metastable Dark Energy and Tensions in the Estimation of Cosmological Parameters

Exploring the cosmic dawn and epoch of reionization with 21cm line

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