C OSMIC A NISOTROPIES FROM Q UASARS Anisotropies co(s)miques avec les quasars V INCENT P ELGRIMS – Dautreppe 2018 Dernière Nouvelles de l’Univers – Grenoble, Décembre 6, 2018
Cosmological Principle The ΛCDM: successful concordance model of cosmology Cosmological principle + General Relatjvity → FLRW Universes [e.g Trodden & Carroll 2004] [Planck 2013 XV] Though, some anomalies : ● Low- l defjcit in the TT angular power spectrum ● Small temperature variance ● Dipole and quadrupole alignment of moments ● Excess of Integrated Sachs-Wolfe efgect signal ● ... ● Departure from isotropic H 0 from SNIa ● Extreme-scale alignments of quasar (optjcal) polarizatjon vectors ● … V. Pelgrims 2
Cosmological Principle The Universe has to be homogeneous and isotropic when it is viewed at suffjciently large scale. It requires/implies that the part of the Universe that we observe and study is a statjstjcally representatjve sample of its entjrety. ➢ Homogeneity = same observatjon can be made from wherever ➢ Isotropy = same observatjon can be made by looking in whatever directjon ➢ Isotropy for all observers implies homogeneity ➢ Homogeneity for all does not imply isotropy ➢ Bianchi cosmological models that are homogeneous and anisotropic Resurgent interests to explain some anomalies such as: ● Low- l defjcit in the TT angular power spectrum ● Small temperature variance ● Dipole and quadrupole alignment of moments [Planck 2013 XV] ● Excess of Integrated Sachs-Wolfe efgect signal ● ... ● Departure from isotropic H 0 from SNIa ● Extreme-scale alignments of quasar (optjcal) polarizatjon vectors ● … Isotropy appears to be questjonable … V. Pelgrims 3
Cosmological Principle The Universe has to be homogeneous and isotropic when it is viewed at suffjciently large scale. It requires/implies that the part of the Universe that we observe and study is a statjstjcally representatjve sample of its entjrety. ➢ Homogeneity = same observatjon can be made from wherever ➢ Isotropy = same observatjon can be made by looking in whatever directjon ➢ Isotropy for all observers implies homogeneity ➢ Homogeneity for all does not imply isotropy ➢ Bianchi cosmological models are homogeneous but anisotropic Resurgent interests to explain some anomalies such as: ● Low- l defjcit in the TT angular power spectrum ● Small temperature variance ● Dipole and quadrupole alignment of moments [Springel et al. 2005] ● Excess of Integrated Sachs-Wolfe efgect signal ● ... ● Departure from isotropic H 0 from SNIa ● Extreme-scale alignments of quasar (optjcal) polarizatjon vectors ● … Isotropy appears to be questjonable … Homogeneity as well, at least the value of the homogeneity scale has long been debated and most recently with quasars. V. Pelgrims 4
Quasars and Cosmology Large-scale alignments of quasar polarizatjon vectors Cosmological principle: Isotropy and Homogeneity Quasars: general propertjes and polarizatjon Quasars and extreme-scale correlatjons Quasars and large-scale structures Cosmic Anisotropies from Quasars from polarizatjon to structural-axis alignments V.P. 2016, astro-ph: [arXiv:1604.05141] V. Pelgrims 5
Polarizatjon of light E B Un-polarized Polarized V. Pelgrims 6
Polarizatjon of light E B Un-polarized Polarized N ψ = 30° p lin = 0 % p lin >> 0 % V. Pelgrims 7
Quasars: bright point-like sources in the Universe ~ 10’’ [Deep Field from Hubble Space Telescope] V. Pelgrims 8
Quasars: some propertjes ● Most luminous Actjve Galactjc Nuclei ● Ultra-bright point-like sources ● Emit light in the whole spectrum ● Observable at the far reaches of the Universe ● Tiny region at the center of a Galaxy (~ 10 -3 – 10 -4 pc) → matuer accretjon onto a Super Massive Black Hole (>10 8 M ʘ ) ● Light is polarized at various wavelengths → no spherical symmetry ~ 10’’ [QSO 1229+204; Hutchings et al. 1994 (HST)] V. Pelgrims 9
Quasars: some propertjes ● Most luminous Actjve Galactjc Nuclei ● Ultra-bright point-like sources ● Emit light in the whole spectrum ● Observable at the far reaches of the Universe ● Tiny region at the center of a Galaxy (~ 10 -3 – 10 -4 pc) → matuer accretjon onto a Super Massive Black Hole (>10 8 M ʘ ) ● Light is polarized at various wavelengths → no spherical symmetry [Urry & Padovani; unified model] V. Pelgrims 10
Quasars: some propertjes ● Most luminous Actjve Galactjc Nuclei ● Ultra-bright point-like sources ● Emit light in the whole spectrum ● Observable at the far reaches of the Universe [Smith et al. 2004] ● Tiny region at the center of a Galaxy (~ 10 -3 – 10 -4 pc) → matuer accretjon onto a Super Massive Black Hole (>10 8 M ʘ ) ● Light is polarized at various wavelengths → no spherical symmetry [Hutsemékers et al. 2015] ● Very-high resolutjon observatjons of a few showed the optjcal polarizatjon orientatjon relates to structural axis ~ 10’’ of the source (blue/UV contjnuum or radio jet) [Borguet et al. 2005] → parallel or perpendicular to the spin axis at optjcal wavelength V. Pelgrims 11
Quasars: some propertjes ● Most luminous Actjve Galactjc Nuclei ● Ultra-bright point-like sources ● Emit light in the whole spectrum ● Observable at the far reaches of the Universe ● Tiny region at the center of a Galaxy (~ 10 -3 – 10 -4 pc) → matuer accretjon onto a Super Massive Black Hole (>10 8 M ʘ ) ● Light is polarized at various wavelengths → no spherical symmetry ● Very-high resolutjon observatjons of a few showed the optjcal polarizatjon orientatjon relates to structural axis of the source (blue/UV contjnuum or ~ 10’’ radio jet) [Borguet et al. 2005] [QSO 1229+204; Hutchings et al. 1994 (HST)] ● Similar relatjon at other wavelength V. Pelgrims 12
Quasars and extreme-scale correlatjons Extreme-scale alignments of quasar optjcal polarizatjon vectors 0.7 < z < 1.5 A3 Originally discovered: [Hutsemékers 1998] Confjrmed with: ● new observatjons [Hutsemékers & Lamy 2001 ; Declinatjon (°) Sluse et al. 2005] ● independent analyses [Hutsemékers et al. 2005] [Hutsemékers & Lamy 2001 ; Jain et al. 2004 ; Cabanac et al. 2005 ; Hutsemékers et al. 2005 ; Pelgrims & Cudell 2012 ; Pelgrims 2018] Right Ascension (°) Probability of uniformity ~ 6 10 -5 V. Pelgrims 13
Quasars and extreme-scale correlatjons Extreme-scale alignments of quasar optjcal polarizatjon vectors [Hutsemékers et al. 2005] ➢ Current sample: 0.7 < z < 1.5 A3 355 quasars with reliable opt. pol. ➢ Signifjcant orientatjon correlatjons within few Gpc scale regions Declinatjon (°) [Hutsemékers et al. 2005] Right Ascension (°) Probability of uniformity ~ 6 10 -5 V. Pelgrims 14
Quasars and extreme-scale correlatjons Extreme-scale alignments of quasar optjcal polarizatjon vectors [Hutsemékers et al. 2005] 0.0 < z < 1.0 A1 low z ➢ Current sample: 355 quasars with reliable opt. pol. ➢ Signifjcant orientatjon correlatjons within few Gpc scale regions Declinatjon (°) [Hutsemékers et al. 2005] ➢ Redshifu dependence of preferred orientatjon Right Ascension (°) V. Pelgrims 15
Quasars and extreme-scale correlatjons Extreme-scale alignments of quasar optjcal polarizatjon vectors [Hutsemékers et al. 2005] 1.0 < z < 2.3 A1 ➢ Current sample: 355 quasars with reliable opt. pol. ➢ Signifjcant orientatjon correlatjons within few Gpc scale regions Declinatjon (°) [Hutsemékers et al. 2005] ➢ Redshifu dependence of preferred orientatjon Right Ascension (°) V. Pelgrims 16
Quasars and extreme-scale correlatjons Extreme-scale alignments of quasar optjcal polarizatjon vectors [Hutsemékers et al. 2005] 1.0 < z < 2.3 A1 ➢ Current sample: 355 quasars with reliable opt. pol. ➢ Signifjcant orientatjon correlatjons within few Gpc scale regions Declinatjon (°) [Hutsemékers et al. 2005] ➢ Redshifu dependence of preferred orientatjon ➢ Statjstjcally signifjcant inside the whole sample (including LEE) → probability of randomness <0.1% using dedicated statjstjcal tests Right Ascension (°) V. Pelgrims 17
Quasars and extreme-scale correlatjons Extreme-scale alignments of quasar optjcal polarizatjon vectors [Hutsemékers et al. 2005] No satjsfactory explanatjon despite ➢ Current sample: the various investjgated scenarios 355 quasars with reliable opt. pol. ● Cosmic strings/loops ● Cosmological-scale magnetjc fjeld ➢ Signifjcant orientatjon correlatjons ● Axion-like Dark Matuer partjcle within few Gpc scale regions ● Birefringence of the Universe ● Anisotropic cosmological expansion ➢ Redshifu dependence of preferred ● ... orientatjon [V.P. & Cudell 2014 ; V.P. 2014] ✔ Confjrmatjon of alignments with new and ➢ Statjstjcally signifjcant inside the whole statjstjcally independent methods ✔ Confjrmatjon of redshifu dependence but sample (including LEE) with no smooth and contjnuous rotatjon as → probability of randomness <0.1% suggested before using dedicated statjstjcal tests [V.P. 2018] ✔ Robustness of alignments regarding interstellar polarizatjon contaminatjon Stjll not understood today ! evaluated from Planck map ✔ But contaminatjon is detected for ~ 30% of the sample V. Pelgrims 18
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