<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">Dear all,<div class=""><br class=""></div><div class=""><br class=""></div><div class="">this Wednesday we continue with our Astro Journal Club at 3 p.m. (sharp) in the seminar room F-201 of the Physics Department. Krešimir is going to talk about the dynamics of the Local Group of galaxies. </div><div class=""><br class=""></div><div class="">Presenter: Krešimir Tisanić</div><div class=""><br class=""></div><div class="">Title: The dipole repeller</div><div class=""><br class=""></div><div class="">Authors: Hoffman Y., Pomarede D., Tully R.B., Courtois H.M.</div><div class=""><br class=""></div><div class="">Abstract:</div><div class=""><div style="margin: 0px; line-height: normal;" class="">Our Local Group of galaxies is moving with respect to the cosmic microwave background (CMB) with a velocity<span style="line-height: normal;" class=""> </span>of v_CMB = 631 +- 20 kms^-1 and participates in a bulk flow that extends out to distances of ~20,000 kms^-1 or more. There has been an implicit assumption that overabundances of galaxies induce the Local Group motion. Yet underdense regions push as much as overdensities attract, but they are deficient in light and consequently difficult to chart. It was suggested a decade ago that an underdensity in the northern hemisphere roughly 15,000 kms^-1<span style="line-height: normal;" class=""> </span>away contributes significantly to the observed flow. We show here that repulsion from an underdensity is important and that the dominant influences causing the observed flow are a single attractor — associated with the Shapley concentration — and a single previously unidentified repeller, which contribute roughly equally to the CMB dipole. The bulk flow is closely anti-aligned with the repeller out to 16,000 +- 4,500 kms^-1. This ‘dipole repeller’ is predicted to be associated with a void in the distribution of galaxies.</div></div><div class=""><br class=""></div><div class="">Link: <a href="http://www.nature.com/articles/s41550-016-0036" class="">http://www.nature.com/articles/s41550-016-0036</a> </div><div class=""><br class=""></div><div class=""><br class=""></div><div class="">If you have recently read interesting astrophysics paper you would like to present, please contact me via e-mail: <a href="mailto:lceraj@phy.hr" class="">lceraj@phy.hr</a></div><div class=""><br class=""></div><div class=""><br class=""></div><div class="">See you on Wednesday.</div><div class=""><br class=""></div><div class="">Cheers,</div><div class="">Lana</div><div class=""><br class=""></div></body></html>