Evidence for a high-z ISW signal from supervoids in the distribution of eBOSS quasars

Kovács, A.; Beck, R.; Smith, A.; Rácz, G.; Csabai, I.; Szapudi, I.
Referencia bibliográfica

Monthly Notices of the Royal Astronomical Society

Fecha de publicación:
Número de autores
Número de autores del IAC
Número de citas
Número de citas referidas
The late-time integrated Sachs-Wolfe (ISW) imprint of $R\gtrsim 100~h^{-1}\, \mathrm{Mpc}$ superstructures is sourced by evolving large-scale potentials due to a dominant dark energy component in the ΛCDM model. The aspect that makes the ISW effect distinctly interesting is the repeated observation of stronger-than-expected imprints from supervoids at z ≲ 0.9. Here we analyse the un-probed key redshift range 0.8 < z < 2.2 where the ISW signal is expected to fade in ΛCDM, due to a weakening dark energy component, and eventually become consistent with zero in the matter dominated epoch. On the contrary, alternative cosmological models, proposed to explain the excess low-z ISW signals, predicted a sign-change in the ISW effect at z ≍ 1.5 due to the possible growth of large-scale potentials that is absent in the standard model. To discriminate, we estimated the high-z ΛCDM ISW signal using the Millennium XXL mock catalogue, and compared it to our measurements from about 800 supervoids identified in the eBOSS DR16 quasar catalogue. At 0.8 < z < 1.2, we found an excess ISW signal with AISW ≍ 3.6 ± 2.1 amplitude. The signal is then consistent with the ΛCDM expectation (AISW = 1) at 1.2 < z < 1.5 where the standard and alternative models predict similar amplitudes. Most interestingly, we also observed an opposite-sign ISW signal at 1.5 < z < 2.2 that is in 2.7σ tension with the ΛCDM prediction. Taken at face value, these recurring hints for ISW anomalies suggest an alternative growth rate of structure in low-density environments at $\sim 100~h^{-1}\, \mathrm{Mpc}$ scales.
Proyectos relacionados
El andamiaje invisible del espacio
Cosmología con Trazadores de la Estructura a Gran Escala del Universo
El Fondo Cósmico de Microondas (FCM) contiene la información estadística de las semillas primigenias que han dado lugar a la formación de todas las estructuras en el Universo. Su contrapartida natural en el Universo local es la distribución de las galaxias que surgen como resultado del crecimiento gravitatorio de aquellas fluctuaciones de densidad