We show herein that a proto-cluster of Lyα emitting galaxies, spectroscopically confirmed at redshift 6.5, produces a remarkable number of ionising continuum photons. We start from the Lyα fluxes measured in the spectra of the sources detected spectroscopically. From these fluxes we derive the ionising emissivity of continuum photons of the proto-cluster, which we compare with the ionising emissivity required to reionise the proto-cluster volume. We find that the sources in the proto-cluster are capable of ionising a large bubble, indeed larger than the volume occupied by the proto-cluster
This section includes scientific and technological news from the IAC and its Observatories, as well as press releases on scientific and technological results, astronomical events, educational projects, outreach activities and institutional events.
An ionised bubble powered by a proto-cluster at z = 6.5Advertised on
Young stars found in the oldest and most massive galaxies in the Universe
Elliptical and lenticular galaxies (collectively called early-type galaxies) are the oldest and most massive galaxies in the Universe. These galaxies were built up rapidly (in less than thousand million years) and therefore, their stars are generally ancient and cool, meaning that they mainly shine in the optical and infrared spectral ranges. However, any hot young stars that might be present are difficult to detect in these spectral ranges. The study, based on 30,000 early-type galaxy spectra from the Sloan Digital Sky Survey BOSS has analysed the UV spectral range to detect the youngAdvertised on
Scientists discover the first pulsating white dwarf in an eclipsing binary system
An international research, led by scientists from the University of Sheffield and with the participation of the Instituto de Astrofísica de Canarias, has discovered, using the HiPERCAM instrument of the Gran Telescopio Canarias at the Roque de los Muchachos Observatory (Garafía, La Palma), an ancient pulsating star in a double star system. The discovery, which is published in the journal Nature Astronomy, provides important information about how stars like our Sun evolve and eventually die.Advertised on
A step forward to solve the mystery of ultra-diffuse galaxies
A study by the Instituto de Astrofísica de Canarias (IAC), led by researchers Nushkia Chamba, Ignacio Trujillo and Johan H. Knapen, reveals that the enigmatic ultra-diffuse galaxies, very low-luminosity and low-density star galaxies, are similar in size to dwarf galaxies. The results, which are published in the journal Astronomy & Astrophysics, provide new clues about the number and type of galaxies in our Universe and about the nature of dark matter.Advertised on
Are ultra-diffuse galaxies Milky Way-sized?
Now almost 70 years since its introduction, the effective or half-light radius has become a very popular choice for characterising galaxy size. However, the effective radius measures the concentration of light within galaxies and thus does not capture our intuitive definition of size which is related to the edge or boundary of objects. For this reason, we aim to demonstrate the undesirable consequence of using the effective radius to draw conclusions about the nature of faint ultra-diffuse galaxies (UDGs) when compared to dwarfs and Milky Way-like galaxies. Instead of the effective radiusAdvertised on
Sucessful test of new technology which should help to discover “other Earths”
A scientific team, led by the Max Planck Institute for Quantum Optics, with participation from the Instituto de Astrofísica de Canarias, confirms the high degree of precision of the new calibration system known as a “laser frequency comb” which could be the key to the detection of planets like the Earth. The study is published in the journal Nature Astronomy.Advertised on