Dark matter: evidence and candidates Astrophysical evidences - PowerPoint PPT Presentation

. . . . . . Key Laboratory of Particle Astrophysics, Mar 2014 Dark matter: evidence and candidates Zhao-Huan Yu (IHEP) March 14, 2014 Institute of High Energy Physics, CAS Dark matter: evidence and candidates Astrophysical evidences Conclusions Particle candidates Cosmological considerations 1 / 23 . . . . . . . . . . . . . . . . Zhao-Huan Yu ( 余钊焕 )

. . . . . . Astrophysical evidences Cosmological considerations Particle candidates Conclusions Dark matter (DM) in the Universe Dark matter exists at various scales in the Universe. (galaxies, clusters, large scale structures, cosmological scale) However, its microscopic property remains unknown. Zhao-Huan Yu (IHEP) Dark matter: evidence and candidates Mar 2014 2 / 23 . . . . . . . . . . . . . . . .

dispersion of galaxies in the Coma cluster was . . . . . . Astrophysical evidences Mar 2014 Dark matter: evidence and candidates Zhao-Huan Yu (IHEP) Typical spiral galaxy: [Kent & Gunn, 1982] Mass-to-light ratio matter. far too large to be supported by the luminous In 1933, Fritz Zwicky found that the velocity 3 / 23 Particle candidates Conclusions Cosmological considerations . . . . . . . . . . . . . . . . Coma cluster ( 后发座星系团 ) 大熊 小狮 狮子 猎犬 后发 室女 牧夫 北冕

dispersion of galaxies in the Coma cluster was . . . . . . Astrophysical evidences Mar 2014 Dark matter: evidence and candidates Zhao-Huan Yu (IHEP) Typical spiral galaxy: [Kent & Gunn, 1982] Mass-to-light ratio matter. far too large to be supported by the luminous In 1933, Fritz Zwicky found that the velocity 3 / 23 Particle candidates Conclusions Cosmological considerations . . . . . . . . . . . . . . . . Coma cluster ( 后发座星系团 ) 大熊 小狮 狮子 猎犬 后发 室女 牧夫 北冕

. . . . . . Astrophysical evidences Mar 2014 Dark matter: evidence and candidates Zhao-Huan Yu (IHEP) [Kent & Gunn, 1982] matter. far too large to be supported by the luminous In 1933, Fritz Zwicky found that the velocity 3 / 23 Conclusions Cosmological considerations Particle candidates . . . . . . . . . . . . . . . . Coma cluster ( 后发座星系团 ) 大熊 小狮 狮子 猎犬 后发 dispersion of galaxies in the Coma cluster was 室女 牧夫 北冕 Mass-to-light ratio Υ Coma ∼ 260 Υ ⊙ Typical spiral galaxy: O ( 10 )Υ ⊙

According to Newton ’ s law, the relation . . . . . . [Corbelli & Salucci, astro-ph/9909252] Mar 2014 Dark matter: evidence and candidates Zhao-Huan Yu (IHEP) . . should be within radius mass and the between the rotation velocity Triangulum galaxy M33 Astrophysical evidences matter . found evidence for non-luminous curves of spiral galaxies and also In the 1970s, Vera Rubin and her Spiral galaxies: rotation curves Conclusions Particle candidates Cosmological considerations 4 / 23 . . . . . . . . . . . . . . . . collaborators measured the rotation

According to Newton ’ s law, the relation . . . . . . Astrophysical evidences Mar 2014 Dark matter: evidence and candidates Zhao-Huan Yu (IHEP) . . should be within radius mass and the between the rotation velocity [Corbelli & Salucci, astro-ph/9909252] 4 / 23 In the 1970s, Vera Rubin and her Cosmological considerations matter . found evidence for non-luminous curves of spiral galaxies and also Triangulum galaxy M33 Spiral galaxies: rotation curves Conclusions Particle candidates . . . . . . . . . . . . . . . . collaborators measured the rotation M33 dark matter halo stellar disk gas

. . . . . . found evidence for non-luminous Mar 2014 Dark matter: evidence and candidates Zhao-Huan Yu (IHEP) . . Astrophysical evidences Triangulum galaxy M33 matter . [Corbelli & Salucci, astro-ph/9909252] curves of spiral galaxies and also Conclusions Cosmological considerations Particle candidates 4 / 23 Spiral galaxies: rotation curves In the 1970s, Vera Rubin and her . . . . . . . . . . . . . . . . collaborators measured the rotation According to Newton ’ s law, the relation between the rotation velocity v and the M33 mass M ( r ) within radius r should be dark matter halo v 2 r = G N M ( r ) stellar disk r 2 gas v ∝ r − 1 / 2 M ( r ) = constant ⇒ M ( r ) ∝ r ⇒ v = constant

. . . . . . Perturbed by Neptune (discovered in 1846) Mar 2014 Dark matter: evidence and candidates Zhao-Huan Yu (IHEP) Modify known physical laws! Update Newtonian mechanics to general relativity Anomalous perihelion precession of Mercury Search for new objects/substances responsible for it! Unexpected movement of Uranus Astrophysical evidences How can we explain an anomalous phenomenon? Conclusions Particle candidates Cosmological considerations 5 / 23 . . . . . . . . . . . . . . . .

. . . . . . Astrophysical evidences Mar 2014 Dark matter: evidence and candidates Zhao-Huan Yu (IHEP) Modify known physical laws! Update Newtonian mechanics to general relativity Anomalous perihelion precession of Mercury Search for new objects/substances responsible for it! 5 / 23 Unexpected movement of Uranus How can we explain an anomalous phenomenon? Conclusions Particle candidates Cosmological considerations . . . . . . . . . . . . . . . . ⇓ Perturbed by Neptune (discovered in 1846)

. . . . . . Astrophysical evidences Mar 2014 Dark matter: evidence and candidates Zhao-Huan Yu (IHEP) Modify known physical laws! Update Newtonian mechanics to general relativity Anomalous perihelion precession of Mercury Search for new objects/substances responsible for it! 5 / 23 Unexpected movement of Uranus How can we explain an anomalous phenomenon? Conclusions Particle candidates Cosmological considerations . . . . . . . . . . . . . . . . ⇓ Perturbed by Neptune (discovered in 1846)

. . . . . . Astrophysical evidences Mar 2014 Dark matter: evidence and candidates Zhao-Huan Yu (IHEP) Modify known physical laws! Update Newtonian mechanics to general relativity Anomalous perihelion precession of Mercury Search for new objects/substances responsible for it! 5 / 23 Unexpected movement of Uranus How can we explain an anomalous phenomenon? Conclusions Particle candidates Cosmological considerations . . . . . . . . . . . . . . . . ⇓ Perturbed by Neptune (discovered in 1846)

. . . . . . Astrophysical evidences Mar 2014 Dark matter: evidence and candidates Zhao-Huan Yu (IHEP) Modify known physical laws! Anomalous perihelion precession of Mercury Search for new objects/substances responsible for it! 5 / 23 Unexpected movement of Uranus How can we explain an anomalous phenomenon? Conclusions Particle candidates Cosmological considerations . . . . . . . . . . . . . . . . ⇓ Perturbed by Neptune (discovered in 1846) ⇓ Update Newtonian mechanics to general relativity

. . . . . . Astrophysical evidences Mar 2014 Dark matter: evidence and candidates Zhao-Huan Yu (IHEP) Modify known physical laws! Anomalous perihelion precession of Mercury Search for new objects/substances responsible for it! 5 / 23 Unexpected movement of Uranus How can we explain an anomalous phenomenon? Conclusions Particle candidates Cosmological considerations . . . . . . . . . . . . . . . . ⇓ Perturbed by Neptune (discovered in 1846) ⇓ Update Newtonian mechanics to general relativity

. . . . . . ( baryonic dark matter : brown dwarfs, jupiters, stellar black-hole Mar 2014 Dark matter: evidence and candidates Zhao-Huan Yu (IHEP) (not constituted by baryons) Nonbaryonic Dark Matter Consider new substances [EROS-2 coll., astro-ph/0607207] (95% C.L.) MACHO fraction in the Galactic dark matter halo: remnants, white dwarfs, neutron stars, ...) MAssive Compact Halo Objects (MACHOs) Astrophysical evidences Consider new objects Difficult to coherently explain data at all scales with one model. [Milgrom, ApJ, 1983] How about the anomalous phenomena here? Conclusions Particle candidates Cosmological considerations 6 / 23 . . . . . . . . . . . . . . . . Modify physical laws ⇒ MOdified Newtonian Dynamics (MOND)

. . . . . . Astrophysical evidences Mar 2014 Dark matter: evidence and candidates Zhao-Huan Yu (IHEP) (not constituted by baryons) Nonbaryonic Dark Matter Consider new substances [EROS-2 coll., astro-ph/0607207] remnants, white dwarfs, neutron stars, ...) ( baryonic dark matter : brown dwarfs, jupiters, stellar black-hole 6 / 23 Difficult to coherently explain data at all scales with one model. [Milgrom, ApJ, 1983] How about the anomalous phenomena here? Conclusions Particle candidates Cosmological considerations . . . . . . . . . . . . . . . . Modify physical laws ⇒ MOdified Newtonian Dynamics (MOND) Consider new objects ⇒ MAssive Compact Halo Objects (MACHOs) MACHO fraction in the Galactic dark matter halo: < 8% (95% C.L.)

. . . . . . Astrophysical evidences Mar 2014 Dark matter: evidence and candidates Zhao-Huan Yu (IHEP) (not constituted by baryons) [EROS-2 coll., astro-ph/0607207] remnants, white dwarfs, neutron stars, ...) ( baryonic dark matter : brown dwarfs, jupiters, stellar black-hole Difficult to coherently explain data at all scales with one model. [Milgrom, ApJ, 1983] How about the anomalous phenomena here? Conclusions Particle candidates Cosmological considerations 6 / 23 . . . . . . . . . . . . . . . . Modify physical laws ⇒ MOdified Newtonian Dynamics (MOND) Consider new objects ⇒ MAssive Compact Halo Objects (MACHOs) MACHO fraction in the Galactic dark matter halo: < 8% (95% C.L.) Consider new substances ⇒ Nonbaryonic Dark Matter