Figure 2: Comparison of absorption features seen in the spectra of the lensed images A (red line) and B (blue line), taken in 2010 February (left) and 2014 April (right). Absorption profiles of three elements (carbon, nitrogen, and hydrogen) are shown from top to bottom. The horizontal axis represents an outflow velocity from the light source, defined as negative if it heads towards Earth. The shaded area shows a clear difference between the images A and B. Arrows highlight features that are not related to the outflow. (Credit: Shinshu University).
Figure 3: Schematic drawing of the gravitational lensing effect, showing SDSS J1029+2623 (at ~10 billion light years), an intervening cluster of galaxies (at ~5 billion light years), and Earth. The light from quasar reaches Earth through three different routes. Images B and C need an extra time of ~744 days to reach Earth compared to image A. (Credit: Shinshu University, the National Astronomical Observatory of Japan)
Figure 4：Same as Figure 2, but for comparison of absorption features seen in images A (left) and B (right), taken in 2010 February (black) and 2014 April (red/blue). Both did not show any clear time variation in profile, although carbon absorption became slightly shallow. (Credit: Shinshu University).
Figure 5: Possible locations of gas clouds in the outflow shown in an artist's rendition of the central region of the quasar. The outflow is gas streaming outward along the curved mesh, which is distinguished from a jet that is blowing vertically. The lines A and B indicate the light paths observed. A cloud along a sightline A creates absorption only in image A, while those along both sightlines of A and B make absorption features in both images. The current observations do not give information on the size, shape, or density of the clouds. (Credit: Shinshu University).
- The authors of the paper are T. Misawa (Shinshu University, Japan), N. Inada (Nara National College of Technology, Japan), M. Oguri (The University of Tokyo, Japan), P. Gandhi (Durham University, UK), T. Horiuchi, S. Koyamada, R. Okamoto (Shinshu University, Japan).
- The corresponding redshift is z~2.197.
- Because their appearance is star-like, they are called "quasi-stellar objects" and abbreviated as quasars.
- See the previous web release at the Subaru Telescope website, http://subarutelescope.org/Pressrelease/2013/02/18/index.html
- We can examine the physical properties of outflows through absorption features that are recorded in spectra (rainbows) of quasars.
- The light from a distant source is bent by the gravitational field around massive objects between the source and the observer. As a result, the light is split into multiple images and/or magnified. This effect is one of the predictions of Einstein's general theory of relativity.
- This is a massive structure consisting of several hundreds to thousands of galaxies, intra-cluster gas, and a large amount of dark matter. A cluster of galaxies can cause a strong gravitationally lensing effect.
- 1 arcsec (1") is a unit of angle, defined as 1/3600 of 1 degree. Human eyes cannot distinguish such a small angle.
- This can be measured by monitoring and comparing variation patterns of image brightness. (Fohlmeister, J. et al., 2013, The Astrophysical Journal, vol. 764, 186).
- This is a phenomenon in which electrons are captured by cations in plasma. Recombination rate depends on the electron density, and the relative abundance of specific ions depends on the distance from the flux source.
- The volume density of air particles on the ground is of order of 1019 per cubic centimeter.
- Size of gas clouds d, its distance from the flux source r, and separation angle between the lensed images θ, should satisfy the relation d ＜ rθ, in order that two lensed images have different absorption profiles.
- Gas volume density can be estimated through examination of the ionization conditions of the outflow (for example, Hamann et al. 2013, MNRAS, 435, 133).
- A substantial fraction of these have been discovered by an international team led by Naohisa Inada and Masamune Oguri (both are members of the current research team).