引力波源宇宙原初引力波课件.ppt

1、1Gravitational-wave standard sirens as a probe of cosmologyWen ZhaoDepartment of AstronomyUniversity of Science and Technology of ChinaBased on: WZ, Van Den Broeck, Baskaran & Li, Phys.Rev.D83, 023005 (2011)提提 纲纲v引力波源与引力波探测器引力波源与引力波探测器v引力波源作为标准铃声引力波源作为标准铃声v在宇宙学中的应用在宇宙学中的应用2引力波源与引力波探测器引力波源与引力波探测器v宇宙学

2、的宇宙学的“引力波源引力波源” 宇宙原初引力波宇宙原初引力波(PGW)(PGW)，宇宙弦产生引力波，早期宇宙相变产生引力波，宇宙弦产生引力波，早期宇宙相变产生引力波v“超大质量黑洞超大质量黑洞”作为引力波源作为引力波源 106 - 109106 - 109太阳质量的双黑洞系统太阳质量的双黑洞系统(SMBH)(SMBH)v“中子星、恒星质量黑洞中子星、恒星质量黑洞”作为引力波源作为引力波源 太阳质量的黑洞，中子星双星系统太阳质量的黑洞，中子星双星系统 (BNS & NSBH)(BNS & NSBH)3引力波源与引力波探测器引力波源与引力波探测器45引力波源作为引力波源作为“标准铃声标准铃声”vI

3、n 1986, Schutz found that the luminosity distance of the binary neutron stars (or black hole) can be independently determined by observing the G.W. generated by this system. If we can also find the EM counterpart, the redshift can also be determined. Thus the dL-z relation can be used to study the e

4、volution of universe. This is the so-called: standard sirens. (Schutz,Nature,1986) characters：1. non-EM method to study the cosmology 2. independent of “cosmic distance ladder”* 测量哈勃常数测量哈勃常数 地面的Adv.LIGO，Adv.VIRGO (BNS, NSBH) * 测量宇宙暗能量测量宇宙暗能量 地面的Einstein Telescope (BNS, NSBH) 空间的LISA (SMBBH) 空间的BBO (

5、BNS, NSBH)引力波源作为引力波源作为“标准铃声标准铃声”v为什么需要别的方法来确定为什么需要别的方法来确定“红移红移”？ * 仅靠引力波的观测无法仅靠引力波的观测无法(很难很难)定出红移定出红移* 打破波源的打破波源的“位置参数位置参数”与与“內秉参数內秉参数”之间的耦合之间的耦合6引力波源作为引力波源作为“标准铃声标准铃声”v怎样确定波源的怎样确定波源的“红移红移”？* 通过引力波探测器的高空间分辨率，找到波源的宿主星系，通过引力波探测器的高空间分辨率，找到波源的宿主星系，通过光谱来确定其红移（空间引力波探测器）通过光谱来确定其红移（空间引力波探测器）（Throne, 1987; W

6、en & Chen, PRD, 2010）* 通过引力潮汐在引力波相位中的体现来确定红移通过引力潮汐在引力波相位中的体现来确定红移(5PN) （Messenger & Read, PRL, 2012）* 找到其光学对应体来确定红移，例如伽玛暴，找到其光学对应体来确定红移，例如伽玛暴，X射线暴等射线暴等789在宇宙学中的应用在宇宙学中的应用- 1. 直接测量哈勃常数直接测量哈勃常数在宇宙学中的应用在宇宙学中的应用- 2. 直接测量哈勃参数的演化直接测量哈勃参数的演化11在宇宙学中的应用在宇宙学中的应用- 3. 区分暗能量与修改引力理论区分暗能量与修改引力理论1213在宇宙学中的应用在宇宙学中的应

7、用- 4. 探测宇宙暗能量探测宇宙暗能量 (WZ, van Broeck, Baskaran & Li, Phys.Rev.D, 2011)vSince 1998, people discovered the an accelerating expansion of the universe by the observations of SNIa. Now the main observations include: SNIa, CMB, BAO, WL, GRB and so on, which all support the LCDM model.vIn this model, 70% e

8、nergy is the so-called dark energy, mimic the cosmological constant.vNow, many dark energy models are suggested: Quinessence, Phantom, Quintom, YMC, HDE, MG and so on. 14Dark Energy ProblemvThe key to distinguish various models is based on the observations of EOS.vIn the near future, the main probes

9、 are still various EM methods: CMB, SNIa, BAO, WL see “Report of DETF” for details.vProblem: Are there any non-EM method? (Komatsu et al. 2010)15Gravitational-wave DetectorsGround-based:LIGO, VIRGO, GEO, TAMAAdv.LIGO, Adv.VIRGO (2015)ET (2020?)Space-based:LISA (2020?)BBO, DECIGO, ASTROD (God Knows!)

10、1617Expanding Universe and Dark EnergyvLet us work with the FLRW universes, which are described by k=0,1,-1 describes the flat, closed and open universe, respectively.vWe consider the universe is filled by the cold dust (baryon and dark matter) and dark energy with the equation of state (EOS) vIn th

11、is universe, the Hubble parameter is calculated by 18Short-hand Gamma-ray burst and Gravitational waves1920Einstein Telescope21Short-hand Gamma-ray BurstsvWe assume gamma radiation is emitted in a narrow cone at a range 20 .vWe only consider the low redshift sources with z 2 .vTotal uncertainty of t

12、he luminosity distance is estimated by 2223Gravitational Wave Standard Sirens24vAs a conservative estimation, we assume 1000 sources ( 1/1000 of the total sources) will be observed by both EM and GW ways.vIn addition to the number of the sources, the redshift distribution of the sources also play a

13、crucial role for the detection of dark energy. * uniform distribution r(z) = constant * non-uniform distribution r(z) peaks at z = 1 (Schneider et al 2001)2526How to break the parameter degeneracy?- Planck CMB PriorvObservations of CMB are always used as the required prior for the detection of dark

14、energy.vCMB is very sensitive for the determination of curvature , baryon and dark matter, which is just complementary with GW method.vThe Fisher matrix for CMB is vNow, let us combine Planck (CMB) and ET (GW) method.vNOTE: it is incorrect to say CMB alone can detect DE.27ET (GW) & JDEM (BAO) & SNAP

15、 (SNIa) 28ConclusionvET (GW) provides a new non-EM method for the detection of dark energy, and the sensitivity is close to the future BAO and SNIa methods.vSimilar to BAO and SNIa methods, Planck (CMB) prior plays a crucial role for the dark energy detection by ET (GW) method.谢谢！谢谢！2930Effects of s

16、ources distribution31Detecting DE by BAO method32Detecting DE by SNIa method引力波源作为引力波源作为“标准铃声标准铃声”v怎样确定波源的怎样确定波源的“红移红移”？* 通过引力波探测器的高空间分辨率，找到波源的宿主星系，通过引力波探测器的高空间分辨率，找到波源的宿主星系，通过光谱来确定其红移（空间引力波探测器）通过光谱来确定其红移（空间引力波探测器）（Throne, 1987; Wen & Chen, PRD, 2010）* 通过引力潮汐在引力波相位中的体现来确定红移通过引力潮汐在引力波相位中的体现来确定红移(5PN) （Messenger & Read, PRL, 2012）* 找到其光学对应体来确定红移，例如伽玛暴，找到其光学对应体来确定红移，例如伽玛暴，X射线暴等射线暴等3334引力波源作为引力波源作为“标准铃声标准铃声”v为什么需要别的方法来确定为什么需要别的方法来确定“红移红移”？ * 仅靠引力波的观测无法仅靠引力波的观测无法(很难很难)定出红移定出红移* 打破波源的打破波源的“位置参数位置参数”与与“內秉参数內秉参数”之间的耦合之间的耦合35