ESA Science & Technology - Publication Archive
Methods. We constructed restframe 8 micron, 12 micron, and total infrared (TIR) luminosity functions (LFs) at 0.15 < z < 2.2 using 4128 infrared sources in the AKARI NEP-Deep field. A continuous filter coverage in the mid-IR wavelength (2.4, 3.2, 4.1, 7, 9, 11, 15, 18, and 24 micron) by the AKARI satellite allowed us to estimate restframe 8 micron and 12 micron luminosities without using a large extrapolation based on an SED fit, which was the largest uncertainty in previous work.
Results. We find that all 8 micron (0.38 < z < 2.2), 12 micron (0.15 < z < 1.16), and TIR LFs (0.2 < z < 1.6) show continuous and strong evolution toward higher redshift. Our direct estimate of 8 micron LFs is useful since previous work often had to use a large extrapolation from the Spitzer 24 micron to 8 micron, where SED modeling is more difficult because of the PAH emissions. In terms of cosmic infrared luminosity density (OmegaIR), which was obtained by integrating analytic fits to the LFs, we find good agreement with previous work at z < 1.2. We find the OmegaIR evolves as proportinal to (1 + z)4.4±1.0. When we separate contributions to OmegaIR by LIRGs and ULIRGs, we found more IR luminous sources are increasingly more important at higher redshift. We find that the ULIRG (LIRG) contribution increases by a factor of 10 (1.8) from z=0.35 to z=1.4.
A&A doi http://dx.doi.org/10.1051/0004-6361/200912983
The Planck mission was conceived in 1992, in the wake of the release of the results from the Cosmic Background Explorer (COBE) satellite (Boggess et al. 1992), notably the measurement by the FIRAS instrument of the shape of the spectrum of the Cosmic Microwave Background (CMB), and the detection by the DMR instrument of the spatial anisotropies of the temperature of the CMB. The latter result in particular led to an explosion in the number of ground-based and suborbital experiments dedicated to mapping of the anisotropies, and to proposals for space experiments both in Europe and the USA.
Methods. The AKARI All-Sky Survey provided the first bright point source catalog detected at 90 micron. Beginning with this catalog, we selected galaxies by matching the AKARI sources with those in the IRAS Point Source Catalog Redshift Survey. We measured the total GALEX FUV and NUV flux densities with a photometry software we specifically developed for this purpose. In a further step we matched this sample with the Sloan Digital Sky Survey (SDSS) and Two Micron All Sky Survey (2MASS) galaxies. With this procedure we obtained a basic sample which consists of 776 galaxies. After removing objects whose photometry was contaminated by foreground sources (mainly in the SDSS), we defined the "secure sample" which contains 607 galaxies.
Results. The sample galaxies have redshifts of <~ 0.15, and their 90-micron luminosities range from 106 to 1012 Lsun, with a peak at 1010 Lsun. The SEDs display a large variety, especially more than four orders of magnitude at the mid-far-infrared (M-FIR), but if we sort the sample with respect to 90 micron, the average SED shows a coherent trend: the more luminous an SED at 90 micron, the redder the global SED becomes. The Mr-NUV - r color-magnitude relation of our sample does not show bimodality, and the distribution is centered on the green valley.
- Remainder of abstract is truncated -
Book published in the series "Astrophysics and Space Science Proceedings"; H. Laakso, M.G.G.T. Taylor, C.P. Escoubet (Eds.), 2010, XX, 489 p., Hardcover, ISBN: 978-90-481-3498-4, © Springer
Since the year 2000 the ESA Cluster mission has been investigating the small-scale structures and processes of the Earth's plasma environment, such as those involved in the interaction between the solar wind and the magnetospheric plasma, in global magnetotail dynamics, in cross-tail currents, and in the formation and dynamics of the neutral line and of plasmoids.
This book contains presentations made at the 15th Cluster workshop held in March 2008. It also presents several articles about the Cluster Active Archive and its datasets, a few overview papers on the Cluster mission, and articles reporting on scientific findings on the solar wind, the magnetosheath, the magnetopause and the magnetotail.
The contents of the book are grouped into seven main parts:
- Part I - Products and Services of the Cluster Active Archive
- Part II - Tools for the CAA Data Analysis
- Part III - Measurement Techniques and Calibration Routines
- Part IV - Magnetospheric Missions
- Part V - Observations of Solar Wind and Magnetosheath
- Part VI - Observations of Magnetopause and Cusp
- Part VII - Observations of Magnetospheric Tail
From prehistoric times, mankind has looked up at the night sky, and puzzled at the changing positions of the stars. How far away they are is a question that has confounded scientists for centuries. Over the last few hundred years, many scientific careers – and considerable resources – have been devoted to measuring their positions and motions with ever increasing accuracy. And in the last two decades of the 20th century, the European Space Agency developed and launched the Hipparcos satellite, around which this account revolves, to carry out these exacting measurements from space.
What has prompted these remarkable developments? Why have governments been persuaded to fund them? What are scientists learning from astronomy's equivalent of the Human Genome Project? This book traces the subject's history, explains why such enormous efforts are considered worthwhile, and interweaves these with a first-hand insight into the Hipparcos project, and how big science is conducted at an international level. The involvement of amateur astronomers, and the Hipparcos contributions to climate research, 'death stars' passing close to the Sun, and the search for extra-solar planets and even intelligent life itself, are some of the surprising facets of this unusual space mission.
Table of Contents
Prologue - Hipparcos Launch
1. Our Place in the Cosmos
2. Why Star Positions?
3. Early History
4. Developments 1850-1980
5. The Push to Space
6. From Concept to Launch
7. Disaster Unfolds
8. Mission Recovery
9. Science in the Making
10. The Finishing Touches
11. Our Galaxy
12. Inside the Stars
13. Our Solar System and Habitability
14. The Future