scholarly journals Connecting the metallicity dependence and redshift evolution of high-mass X-ray binaries

2020 ◽  
Vol 495 (1) ◽  
pp. 771-783 ◽  
Author(s):  
Francesca M Fornasini ◽  
Francesca Civano ◽  
Hyewon Suh
Keyword(s):  
Direct Evidence ◽  
Star Formation Rate ◽  
Formation Rate ◽  
High Mass ◽  
Population Synthesis ◽  
X Ray ◽  
Star Forming ◽  
Best Fitting ◽  
Robust Measurements ◽  
X Ray Binaries

ABSTRACT The integrated X-ray luminosity (LX) of high-mass X-ray binaries (HMXBs) in a galaxy is correlated with its star formation rate (SFR), and the normalization of this correlation increases with redshift. Population synthesis models suggest that the redshift evolution of LX/SFR is driven by the metallicity (Z) dependence of HMXBs, and the first direct evidence of this connection was recently presented using galaxies at z ∼ 2. To confirm this result with more robust measurements and better constrain the LX–SFR–Z relation, we have studied the Z dependence of LX/SFR at lower redshifts. Using samples of star-forming galaxies at z = 0.1–0.9 with optical spectra from the hCOSMOS and zCOSMOS surveys, we stacked Chandra data from the COSMOS Legacy survey to measure the average LX/SFR as a function of Z in three redshift ranges: z = 0.1–0.25, 0.25–0.4, and 0.5–0.9. We find no significant variation of the LX–SFR–Z relation with redshift. Our results provide further evidence that the Z dependence of HMXBs is responsible for the redshift evolution of LX/SFR. Combining all available z > 0 measurements together, we derive a best-fitting LX–SFR–Z relation and assess how different population synthesis models describe the data. These results provide the strongest constraints to date on the LX–SFR–Z relation in the range of 8.0 < 12 + log(O/H) < 9.0.

scholarly journals X-ray binaries as the origin of nebular He II emission in low-metallicity star-forming galaxies

2019 ◽  
Vol 622 ◽  
pp. L10 ◽  
Author(s):  
D. Schaerer ◽  
T. Fragos ◽  
Y. I. Izotov
Keyword(s):  
Star Formation ◽  
Empirical Data ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Theoretical Models ◽  
High Mass ◽  
X Ray ◽  
Star Forming ◽  
Low Metallicity ◽  
X Ray Binaries

The origin of nebular He II emission, which is frequently observed in low-metallicity (O/H) star-forming galaxies, remains largely an unsolved question. Using the observed anticorrelation of the integrated X-ray luminosity per unit of star formation rate (LX/SFR) of an X-ray binary population with metallicity and other empirical data from the well-studied galaxy I Zw 18, we show that the observed He II λ4686 intensity and its trend with metallicity is naturally reproduced if the bulk of He+ ionizing photons are emitted by the X-ray sources. We also show that a combination of X-ray binary population models with normal single and/or binary stellar models reproduces the observed I(4686)/I(Hβ) intensities and its dependency on metallicity and age. We conclude that both empirical data and theoretical models suggest that high-mass X-ray binaries are the main source of nebular He II emission in low-metallicity star-forming galaxies.

scholarly journals High-mass X-ray binaries in nearby metal-poor galaxies: on the contribution to nebular He ii emission

2020 ◽  
Vol 494 (1) ◽  
pp. 941-957 ◽  
Author(s):  
Peter Senchyna ◽  
Daniel P Stark ◽  
Jordan Mirocha ◽  
Amy E Reines ◽  
Stéphane Charlot ◽  
...  
Keyword(s):  
Formation Rate ◽  
Stellar Atmospheres ◽  
High Mass ◽  
Spectral Energy ◽  
X Ray ◽  
Star Forming ◽  
High Ionization ◽  
Binary Evolution ◽  
Joint Contribution ◽  
X Ray Binaries

ABSTRACT Despite significant progress both observationally and theoretically, the origin of high-ionization nebular He ii emission in galaxies dominated by stellar photoionization remains unclear. Accretion-powered radiation from high-mass X-ray binaries (HMXBs) is still one of the leading proposed explanations for the missing He+-ionizing photons, but this scenario has yet to be conclusively tested. In this paper, we present nebular line predictions from a grid of photoionization models with input spectral energy distributions containing the joint contribution of both stellar atmospheres and a multicolour disc model for HMXBs. This grid demonstrates that HMXBs are inefficient producers of the photons necessary to power He ii, and can only boost this line substantially in galaxies with HMXB populations large enough to power X-ray luminosities of 1042 erg s−1 per unit star formation rate (SFR). To test this, we assemble a sample of 11 low-redshift star-forming galaxies with high-quality constraints on both X-ray emission from Chandra and He ii emission from deep optical spectra, including new observations with the MMT. These data reveal that the HMXB populations of these nearby systems are insufficient to account for the observed He ii strengths, with typical X-ray luminosities or upper limits thereon of only 1040–1041 erg s−1 per SFR. This indicates that HMXBs are not the dominant source of He+ ionization in these metal-poor star-forming galaxies. We suggest that the solution may instead reside in revisions to stellar wind predictions, softer X-ray sources, or very hot products of binary evolution at low metallicity.

scholarly journals The High Mass X-ray binaries in star-forming galaxies

2018 ◽  
Vol 14 (S346) ◽  
pp. 332-336
Author(s):  
M. Celeste Artale ◽  
Nicola Giacobbo ◽  
Michela Mapelli ◽  
Paolo Esposito
Keyword(s):  
Luminosity Function ◽  
High Mass ◽  
Population Synthesis ◽  
Host Galaxies ◽  
X Ray ◽  
Star Forming ◽  
Star Formation In Galaxies ◽  
Binary Evolution ◽  
X Ray Binaries ◽  
The Universe

AbstractThe high mass X-ray binaries (HMXBs) provide an exciting framework to investigate the evolution of massive stars and the processes behind binary evolution. HMXBs have shown to be good tracers of recent star formation in galaxies and might be important feedback sources at early stages of the Universe. Furthermore, HMXBs are likely the progenitors of gravitational wave sources (BH–BH or BH–NS binaries that may merge producing gravitational waves). In this work, we investigate the nature and properties of HMXB population in star-forming galaxies. We combine the results from the population synthesis model MOBSE (Giacobbo & Mapelli 2018a) together with galaxy catalogs from EAGLE simulation (Schaye et al. 2015). Therefore, this method describes the HMXBs within their host galaxies in a self-consistent way. We compute the X-ray luminosity function (XLF) of HMXBs in star-forming galaxies, showing that this methodology matches the main features of the observed XLF.

High-mass X-ray binaries: Evolutionary population synthesis modeling

2018 ◽  
Vol 14 (S346) ◽  
pp. 455-458
Author(s):  
Zhao-yu Zuo
Keyword(s):  
High Resolution ◽  
Luminosity Function ◽  
Optical Observations ◽  
High Mass ◽  
Population Synthesis ◽  
X Ray ◽  
Star Forming ◽  
Common Envelope ◽  
X Ray Binaries

AbstractUsing an evolutionary population synthesis code, we modeled the universal, featureless X-ray luminosity function of high-mass X-ray binaries (HMXBs) in star-forming galaxies. We put constraints on the natal kicks, super-Eddington accretion factor, as well as common envelope prescriptions usually adopted (i.e., the αCE formalism and the γ algorithm), and presented the detailed properties of HMXBs under different models, which may be investigated further by future high-resolution X-ray and optical observations.

scholarly journals Sub-galactic scaling relations between X-ray luminosity, star formation rate, and stellar mass

2020 ◽  
Vol 494 (4) ◽  
pp. 5967-5984 ◽  
Author(s):  
K Kouroumpatzakis ◽  
A Zezas ◽  
P Sell ◽  
K Kovlakas ◽  
P Bonfini ◽  
...  
Keyword(s):  
Star Formation ◽  
Star Formation Rate ◽  
Formation Rate ◽  
Star Formation History ◽  
High Mass ◽  
X Ray ◽  
Formation History ◽  
Low Mass ◽  
X Ray Binaries ◽  
Intrinsic Scatter

ABSTRACT X-ray luminosity (LX) originating from high-mass X-ray binaries (HMXBs) is tightly correlated with the host galaxy’s star formation rate (SFR). We explore this connection at sub-galactic scales spanning ∼7 dex in SFR and ∼8 dex in specific SFR (sSFR). There is good agreement with established relations down to SFR ≃ 10−3 M$_{\odot }\, \rm {yr^{-1}}$, below which an excess of X-ray luminosity emerges. This excess likely arises from low-mass X-ray binaries. The intrinsic scatter of the LX–SFR relation is constant, not correlated with SFR. Different star formation indicators scale with LX in different ways, and we attribute the differences to the effect of star formation history. The SFR derived from H α shows the tightest correlation with X-ray luminosity because H α emission probes stellar populations with ages similar to HMXB formation time-scales, but the H α-based SFR is reliable only for $\rm sSFR{\gt }10^{-12}$ M$_{\odot }\, \rm {yr^{-1}}$/M⊙.

scholarly journals High-mass X-ray binaries in a cosmological context

2012 ◽  
Vol 8 (S290) ◽  
pp. 183-184 ◽  
Author(s):  
María Celeste Artale ◽  
Leonardo J. Pellizza ◽  
Patricia B. Tissera ◽  
I. Felix Mirabel
Keyword(s):  
Galaxy Formation ◽  
High Redshift ◽  
High Mass ◽  
Population Synthesis ◽  
High Redshift Galaxies ◽  
X Ray ◽  
Star Forming ◽  
Synthetic Populations ◽  
Cosmological Context ◽  
X Ray Binaries

AbstractRecent observational and theoretical results suggest that the production rates and luminosities of high-mass X-ray binaries depend on metallicity. To test this prediction, we combine HMXB population synthesis results with numerical simulations of galaxy formation to produce synthetic populations of HMXBs in star-forming galaxies, and compare the model predictions to observations of HMXB populations in nearby and high-redshift galaxies. Our models show a fair agreement with observations only when the HMXB production and luminosities are assumed to depend strongly on metallicity.

scholarly journals X-rays from Green Pea analogues

2017 ◽  
Vol 470 (1) ◽  
pp. 606-611 ◽  
Author(s):  
M. Brorby ◽  
P. Kaaret
Keyword(s):  
Star Formation ◽  
Active Galactic Nuclei ◽  
Formation Rate ◽  
Galactic Nuclei ◽  
High Mass ◽  
X Rays ◽  
X Ray ◽  
Star Forming ◽  
Green Pea ◽  
X Ray Binaries

Abstract X-ray observations of two metal-deficient luminous compact galaxies (LCG; SHOC 486 and SDSS J084220.94+115000.2) with properties similar to the so-called Green Pea galaxies were obtained using the Chandra X-ray Observatory. Green Pea galaxies are relatively small, compact (a few kpc across) galaxies that get their green colour from strong [O iii] λ5007 Å emission, an indicator of intense, recent star formation. These two galaxies were predicted to have the highest observed count rates, using the X-ray luminosity–star formation rate (LX–SFR) relation for X-ray binaries, from a statistically complete sample drawn from optical criteria. We determine the X-ray luminosity relative to SFR and metallicity for these two galaxies. Neither exhibits any evidence of active galactic nuclei, and we suspect that the X-ray emission originates from unresolved populations of high-mass X-ray binaries. We discuss the LX–SFR–metallicity plane for star-forming galaxies and show that the two LCGs are consistent with the prediction of this relation. This is the first detection of Green Pea analogues in X-rays.

scholarly journals X-ray properties of He ii λ 1640 emitting galaxies in VANDELS

2020 ◽  
Vol 496 (3) ◽  
pp. 3796-3807
Author(s):  
A Saxena ◽  
L Pentericci ◽  
D Schaerer ◽  
R Schneider ◽  
R Amorin ◽  
...  
Keyword(s):  
Formation Rate ◽  
Galactic Nuclei ◽  
X Ray ◽  
Star Forming ◽  
Set Constraints ◽  
Significant Difference ◽  
Low Metallicity ◽  
Matched Samples ◽  
X Ray Binaries

ABSTRACT We explore X-ray emission from a sample of 18 He ii λ1640 emitting star-forming galaxies at z ∼ 2.3–3.6 from the VANDELS survey in the Chandra Deep Field South, to set constraints on the role of X-ray sources in powering the He ii emission. We find that 4 He ii emitters have tentative detections with S/N ∼ 2 and have X-ray luminosities, LX = 1.5−4.9 × 1041 erg s−1. The stacked luminosity of all 18 He ii emitters is 2.6 × 1041 erg s−1, and that of a subset of 13 narrow He ii emitters (FHWM(He ii) < 1000 km s−1) is 3.1 × 1041 erg s−1. We also measure stacked LX for non-He ii emitters through bootstrapping of matched samples, and find LX = 2.5 × 1041 erg s−1, which is not significantly different from LX measured for He ii emitters. The LX per star formation rate for He ii emitters (log (LX/SFR) ∼ 40.0) and non-emitters (log (LX/SFR) ∼ 39.9) are also comparable and in line with the redshift evolution and metallicity dependence predicted by models. Due to the non-significant difference between the X-ray emission from galaxies with and without He ii, we conclude that X-ray binaries or weak or obscured active galactic nuclei are unlikely to be the dominant producers of He ii ionizing photons in VANDELS star-forming galaxies at z ∼ 3. Given the comparable physical properties of both He ii emitters and non-emitters reported previously, alternative He ii ionizing mechanisms such as localized low-metallicity stellar populations, Pop-III stars, etc. may need to be explored.

Constraining Progenitors of Observed Low-mass X-ray Binaries Using Convection and Rotation-Boosted Magnetic Braking

2021 ◽  
Vol 922 (2) ◽  
pp. 174
Author(s):  
Kenny X. Van ◽  
Natalia Ivanova
Keyword(s):  
Mass Transfer ◽  
Binary Systems ◽  
Formation Rate ◽  
Mass Transfer Rate ◽  
Population Synthesis ◽  
X Ray ◽  
Synthesis Technique ◽  
Low Mass ◽  
Magnetic Braking ◽  
X Ray Binaries

Abstract We present a new method for constraining the mass transfer evolution of low-mass X-ray binaries (LMXBs)—a reverse population synthesis technique. This is done using the detailed 1D stellar evolution code MESA (Modules for Experiments in Stellar Astrophysics) to evolve a high-resolution grid of binary systems spanning a comprehensive range of initial donor masses and orbital periods. We use the recently developed convection and rotation-boosted (CARB) magnetic braking scheme. The CARB magnetic braking scheme is the only magnetic braking prescription capable of reproducing an entire sample of well-studied persistent LMXBs—those with mass ratios, periods, and mass transfer rates that have been observationally determined. Using the reverse population synthesis technique, where we follow any simulated system that successfully reproduces an observed LMXB backward, we have constrained possible progenitors for each observed well-studied persistent LMXB. We also determined that the minimum number of LMXB formations in the Milky Way is 1500 per Gyr if we exclude Cyg X-2. For Cyg X-2, the most likely formation rate is 9000 LMXB Gyr−1. The technique we describe can be applied to any observed LMXB with well-constrained mass ratio, period, and mass transfer rate. With the upcoming GAIA DR3 containing information on binary systems, this technique can be applied to the data release to search for progenitors of observed persistent LMXBs.

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