X-ray Studies of Interstellar and Intergalactic Dust

Transcription

1 X-ray Studies of Interstellar and Intergalactic Dust Lia Corrales Columbia University NASA Earth and Space Science Fellow Advised by Frits Paerels

2 X-ray scattering tools for studying the ISM Cygnus X-3: Grain sizes and spatial distribution Dust-to-gas mass ratio Dust in the intergalactic medium: Future prospects

3 Dust extinction (MRN) X-ray Optical J,H,K,L Herschel Spitzer

4 Optical (DSS) Infrared (SFD) X-ray (RASS) Credit: World Wide Telescope

5 Optical (DSS) Infrared (SFD) X-ray (RASS) Credit: World Wide Telescope

6 X-ray Studies of ISM and IGM Dust Optical (DSS) Infrared (SFD) X-ray (RASS) Credit: World Wide Telescope

7 dust Cygnus X-3 (Chandra)

8 X-ray scattering is a diagnostic tool for ISM grain sizes X-ray light a SGR J (NASA/Swift/Halpern) Strongly forward (small angle) scattering 1 0 a(µm) E(keV) Strongly sensitive to grain size sca / a 4 E 2

9 X-ray scattering is a diagnostic tool for judging distance X-ray light a Strongly forward (small angle) scattering 1 0 a(µm) E(keV) Strongly sensitive to grain size sca / a 4 E 2 Lia Corrales - AAS 223, Jan 2014

10 X-ray scattering is a diagnostic tool for ISM structure X-ray light a SGR J (NASA/Swift/Halpern) sca S O

11 X-ray scattering is a diagnostic tool for ISM structure Screen case SGR J (NASA/Swift/Halpern) sca S O

12 X-ray scattering is a diagnostic tool for ISM structure Screen case SGR J (NASA/Swift/Halpern) sca S O

13 X-ray scattering is a diagnostic tool for ISM structure Screen case SGR J (NASA/Swift/Halpern) sca S O

14 X-ray scattering is a diagnostic tool for ISM structure SGR J (NASA/Swift/Halpern) Uniform case sca S O

15 X-ray scattering tools for studying the ISM Cygnus X-3: Grain sizes and spatial distribution Dust-to-gas mass ratio Dust in the intergalactic medium: Future prospects

16 Cyg X-3 Scattering Halo [1-6 kev] Assume dn da / a p Fit for Cut-off grain size: Power law exponent: Dust mass column: a max p M d Corrales & Paerels (2014)

17 Cyg X-3 Scattering Halo [1-6 kev] Corrales & Paerels (2014)

18 [ 2 =1.3] Bayesian analysis (emcee) finds a population of likely fits a max =0.14 µm p =3.5 sca (1 kev) = 2.4 Corrales & Paerels (2014)

19 Milky Way spiral structure as probed by star forming complexes Perseus Norma-Cygnus Sagittarius Cyg X-3 l = 79.8 b = [Russeil 2003]

20 Bayesian analysis (emcee) finds a population of likely fits 2 1 Corrales & Paerels (2014)

21 [ 2 =2.8] Bayesian analysis (emcee) finds a population of likely fits 2 1 Screen 2: 20% of mass within 1 kpc of Cyg X-3 Screen 1: 80% of mass consistent with Perseus arm a max =0.21 µm p =3.6 sca (1 kev) = 1.9 Corrales & Paerels (2014)

22 X-ray scattering tools for studying the ISM Cygnus X-3: Grain sizes and spatial distribution Dust-to-gas mass ratio Dust in the intergalactic medium: Future prospects

23 X-ray spectral fitting yields a dust-to-gas mass ratio sca (1 kev) = 2.2 Corrales & Paerels (2014)

24 X-ray spectral fitting yields a dust-to-gas mass ratio dust-to-gas mass ratio 1/2 4/3 Corrales & Paerels (2014) Milky Way dust-to-gas mass ratio 1/3 4/3 Milky Way

25 X-ray scattering and absorption gauges:

26 X-ray scattering and absorption gauges: grain size distribution

27 X-ray scattering and absorption gauges: grain size distribution ISM structure

28 X-ray scattering and absorption gauges: grain size distribution ISM structure distance

29 X-ray scattering and absorption gauges: grain size distribution ISM structure distance dust-to-gas ratio

30 X-ray scattering and absorption gauges: grain size distribution ISM structure distance dust-to-gas ratio dust-to-metal ratio

31 X-ray scattering and absorption gauges: grain size distribution ISM structure distance dust-to-gas ratio dust-to-metal ratio dust composition

32 X-ray scattering tools for studying the ISM Cygnus X-3: Grain sizes and spatial distribution Dust-to-gas mass ratio Dust in the intergalactic medium: Future prospects

33 Corrales & Paerels (2012) 1. Could intergalactic dust interfere with dark energy surveys?

34 Petric et al. (2006) z =4.3 quasar kev most of the scattering comes from lower energy d < BUT over-idealized

35 Corrales & Paerels (2012) z =4.3 quasar 1 8 kev where RG-Drude approximation is valid d 10 5 can still be valid (relax constraint) Conclusion: Need to use MIE scattering solution

36 Corrales & Paerels (2012) 1. Could intergalactic dust interfere with dark energy surveys? YES for a population of grey graphite grains: A V A 1.78µm Could we expect large ( grey ) dust grains in the IGM?

37 M82 : Starburst galaxy imaged with Hubble, Spitzer, and Chandra

38 QSO 1Mpc(z =0.36) Ménard+ (2010) Quasar color Angular distance from center of foreground galaxy

39 Corrales & Paerels (2012) 1. Could intergalactic dust interfere with dark energy surveys? YES for a population of grey graphite grains: A V A 1.78µm Could we expect large ( grey ) dust grains in the IGM? PERHAPS due to radiation pressure driven winds (feedback) The dust grains that are efficiently ejected AND survive the process would likely be larger (Davies 1998, Ferrara 1991) 3. X-ray scattering has potential to find exotic dust in exotic places diffuse IGM QSO galaxy halos absorption systems

40 Ménard & Fukugita (2012)

41 It is still a BIG challenge (MIE scattering)

42 X-ray scattering tools for studying the ISM Cygnus X-3: Grain sizes and spatial distribution Dust-to-gas mass ratio Dust in the intergalactic medium: Future prospects

43 X-ray Studies of ISM and IGM Dust Dust in the wind 1067 MSFR argue that the dust in Large Magellanic Cloud (LMC)-like PSF to explain the magnitude of their reddening dwarfs is insufficient signal. We concur with this conclusion. Reproducing the MSFR data in the hybrid model with a physical dust-to-metal mass ratio requires including galaxies up to several times 1010 M#, far larger than the M# baryonic mass of the LMC (van der Marel et al. 2002). Furthermore, Diffuse IGMthe No-Wind simulation predicts a galaxy baryonic mass function that is inconsistent with observations, with Chandra an excessive global fraction of baryons converted to stars (Oppenmodel to be heimer et al. 2010).6 We do not consider the hybrid dustbackground nearly as plausible an explanation of the MSFR results as the Wind model; we present it as a foil to illustrate what would be required Foreground to explain MSFR s findingsgalaxy with dust in low-mass galaxies. For the Wind model, the metals in low-mass galaxies contribute much less reddening than the intergalactic metals (Fig. 5). 4 DISCUSSION For the Wind model to succeed, we require that the dust-to-metal mass ratio in the IGM be comparable to that in the ISM, allowing only 50 per cent of the ISM dust to be destroyed during its expulsion from galaxies and subsequent residence in the IGM. The validity of this assumption is by no means obvious, as the destruction time-scales for 0.01 µm dust grains by thermal sputtering are (nh /10 3 cm 3 ) 1 yr at T = 106 K (Draine & Salpeter 1979, fig. 7), while wind particles in the simulation typically remain in the IGM for 109 yr before re-accreting on to galaxies (Oppenheimer et al. 2010, fig. 2). However, the sputtering rates decline rapidly towards lower temperatures (e.g. a factor of 300 lower at T = 105 K), and with the wind implementation used in this simulation most ejected gas never rises above a few 104 K. Ultraviolet or X-ray background photons arethree another possible destruc- in the A2 simulation. Figure 6. (UV) Eddington ratio as a function of time, for different time intervals tion mechanism IGMofdust, but the intergalactic radiation field (A color for version this figure is available in the online journal.) is much lower intensity than the radiation field dust grains already encounter in galactic star-forming regions.- CU Colloquium - May 7, 2014 Lia Corrales Zu+ (2010) Novak+ (2011)

44 X-ray Studies of ISM and IGM Dust Dust in the wind 1067 MSFR argue that the dust in Large Magellanic Cloud (LMC)-like dwarfs is insufficient to explain the magnitude of their reddening signal.psf We concur with this conclusion. Reproducing Diffuse IGMthe MSFR data in the hybrid model with a physical dust-to-metal mass ratio requires including galaxies up to several times 1010 M#, far larger than the M# baryonic mass of the LMC (van der Marel et al. 2002). Furthermore, the No-Wind simulation predicts a galaxy baryonic mass function that is inconsistent with observations, with an excessive global fraction of baryons converted to stars (OppenForeground galaxy 6 heimer et al. 2010). We do not consider the hybrid dust model to be nearly as plausible an explanation of the MSFR results as the Wind model; we present it as a foil to Chandra illustrate what would be required to explain MSFR s findings with dust in low-mass galaxies. For the background Wind model, the metals in low-mass galaxies contribute much less reddening than the intergalactic metals (Fig. 5). 4 DISCUSSION For the Wind model to succeed, we require that the dust-to-metal mass ratio in the IGM be comparable to that in the ISM, allowing only 50 per cent of the ISM dust to be destroyed during its expulsion from galaxies and subsequent residence in the IGM. The validity of this assumption is by no means obvious, as the destruction time-scales for 0.01 µm dust grains by thermal sputtering are (nh /10 3 cm 3 ) 1 yr at T = 106 K (Draine & Salpeter 1979, fig. 7), while wind particles in the simulation typically remain in the IGM for 109 yr before re-accreting on to galaxies (Oppenheimer et al. 2010, fig. 2). However, the sputtering rates decline rapidly towards lower temperatures (e.g. a factor of 300 lower at T = 105 K), and with the wind implementation used in this simulation most ejected gas never rises above a few 104 K. Ultraviolet or X-ray background photons arethree another possible destruc- in the A2 simulation. Figure 6. (UV) Eddington ratio as a function of time, for different time intervals tion mechanism IGMofdust, but the intergalactic radiation field (A color for version this figure is available in the online journal.) is much lower intensity than the radiation field dust grains already encounter in galactic star-forming regions.- CU Colloquium - May 7, 2014 Lia Corrales Zu+ (2010) Novak+ (2011)

45 A systematic survey for intergalactic dust will affect:

46 A systematic survey for intergalactic dust will affect: cosmic dust and metal budget

47 A systematic survey for intergalactic dust will affect: cosmic dust and metal budget theory of galaxy feedback

48 A systematic survey for intergalactic dust will affect: cosmic dust and metal budget theory of galaxy feedback theory of galaxy evolution

49 A systematic survey for intergalactic dust will affect: cosmic dust and metal budget theory of galaxy feedback theory of galaxy evolution magnitude and timescale of AGN variability

50 A systematic survey for intergalactic dust will affect: cosmic dust and metal budget theory of galaxy feedback theory of galaxy evolution magnitude and timescale of AGN variability high precision cosmology

51 Thank you for your attention. Corrales & Paerels (2014) arxiv: Corrales & Paerels (2012) ApJ 751, 93 Peek, Ménard, & Corrales (2014) coming soon

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