Search

(Abridged) The Maunakea Spectroscopic Explorer (MSE) is an end-to-end science platform for the design, execution and scientific exploitation of spectroscopic surveys. It will unveil the composition and dynamics of the faint Universe and impact nearly every field of astrophysics across all spatial scales, from individual stars to the largest scale structures in the Universe. Major pillars in the science program for MSE include (i) the ultimate Gaia follow-up facility for understanding the chemistry and dynamics of the distant Milky Way, including the outer disk and faint stellar halo at high spectral resolution (ii) galaxy formation and evolution at cosmic noon, via the type of revolutionary surveys that have occurred in the nearby Universe, but now conducted at the peak of the star formation history of the Universe (iii) derivation of the mass of the neutrino and insights into inflationary physics through a cosmological redshift survey that probes a large volume of the Universe with a high galaxy density. MSE is positioned to become a critical hub in the emerging international network of front-line astronomical facilities, with scientific capabilities that naturally complement and extend the scientific power of Gaia, the Large Synoptic Survey Telescope, the Square Kilometer Array, Euclid, WFIRST, the 30m telescopes and many more., Comment: 9 chapters, 301 pages, 100 figures. This version of the DSC is a comprehensive update of the original version, released in 2016, which can be downloaded at arXiv:1606.00043. A detailed summary of the design of MSE is available in the MSE Book 2018, available at arXiv:1810.08695

MSE is an 11.25m aperture observatory with a 1.5 square degree field of view that will be fully dedicated to multi-object spectroscopy. More than 3200 fibres will feed spectrographs operating at low (R ~ 2000 - 3500) and moderate (R ~ 6000) spectral resolution, and approximately 1000 fibers will feed spectrographs operating at high (R ~ 40000) resolution. MSE is designed to enable transformational science in areas as diverse as tomographic mapping of the interstellar and intergalactic media; the in-situ chemical tagging of thick disk and halo stars; connecting galaxies to their large scale structure; measuring the mass functions of cold dark matter sub-halos in galaxy and cluster-scale hosts; reverberation mapping of supermassive black holes in quasars; next generation cosmological surveys using redshift space distortions and peculiar velocities. MSE is an essential follow-up facility to current and next generations of multi-wavelength imaging surveys, including LSST, Gaia, Euclid, WFIRST, PLATO, and the SKA, and is designed to complement and go beyond the science goals of other planned and current spectroscopic capabilities like VISTA/4MOST, WHT/WEAVE, AAT/HERMES and Subaru/PFS. It is an ideal feeder facility for E-ELT, TMT and GMT, and provides the missing link between wide field imaging and small field precision astronomy. MSE is optimized for high throughput, high signal-to-noise observations of the faintest sources in the Universe with high quality calibration and stability being ensured through the dedicated operational mode of the observatory. (abridged), Comment: 210 pages, 91 figures. Exposure draft. Appendices to the Detailed Science Case can be found at http://mse.cfht.hawaii.edu/docs/

Intracluster stellar populations are a natural result of tidal interactions in galaxy clusters. Measuring these populations is difficult, but important for understanding the assembly of the most massive galaxies. The Coma cluster is one of the nearest truly massive galaxy clusters, and is host to a correspondingly large system of globular clusters (GCs). We use imaging from the HST/ACS Coma Cluster Survey to present the first definitive detection of a large population of intracluster GCs (IGCs) that fills the Coma cluster core and is not associated with individual galaxies. The GC surface density profile around the central massive elliptical galaxy, NGC 4874, is dominated at large radii by a population of IGCs that extend to the limit of our data (R<520 kpc). We estimate that there are 47000+/-1600 (random) +4000/-5000 (systematic) IGCs out to this radius, and that they make up ~70% of the central GC system, making this the largest GC system in the nearby Universe. Even including the GC systems of other cluster galaxies, IGCs still make up ~30-45% of the GCs in the cluster core. Observational limits from previous studies of the intracluster light (ICL) suggest that the IGC population has a high specific frequency. If the IGC population has a specific frequency similar to high-S_N dwarf galaxies, then the ICL has a total stellar mass of ~10^12 M_sun within the cluster core. The ICL makes up approximately half of the stellar luminosity and one-third of the stellar mass of the central (NGC4874+ICL) system. The color distribution of the IGC population is bimodal, with blue, metal-poor GCs outnumbering red, metal-rich GCs by a ratio of 4:1. The fraction of red IGCs (20%), and the red color of those GCs, implies that IGCs can originate from the halos of relatively massive, L* galaxies, and not solely from the disruption of dwarf galaxies. (Abridged), Comment: 18 pages, 9 figures, 3 tables. Accepted for publication in the Astrophysical Journal. Typos corrected, and fixed glitch in Figure 1

We present a compilation of galaxies in the NGC 1023 Group, an accumulation of late-type galaxies at a distance of 10 Mpc. Members at high and intermediate luminosities were identified from their spectroscopic velocities. Members at low luminosities were identified from their morphologies on wide-field CCD images. The faint-end slope is in the range -1.27 < alpha < -1.12. There is evidence for two dwarf galaxy populations: one in the halo of NGC 1023 that is dominated by dwarf elliptical galaxies, and one in the infall region surrounding NGC 1023 that contains mainly dwarf irregular galaxies. Similar distinctive populations are observed in the Local Group., Comment: MNRAS, in press

A reconstruction method for recovering the initial conditions of the Universe starting from the present galaxy distribution is presented which guarantees uniqueness of solutions. We show how our method can be used to obtain the peculiar velocities of a large number of galaxies, hence trace galaxies orbits back in time and obtain the entire past dynamical history of the Universe above scales where multi-streaming has not occurred. When tested against a 128^3 LambdaCDM simulation in a box of 200 Mpc/h length, we obtain 60% exact reconstruction on scales above 6 Mpc/h. We apply our method to a real galaxy redshift catalogue, the updated NBG (Nearby Galaxies), containing 1483 galaxies, groups and clusters in a radius of 30 Mpc/h, and reconstruct the peculiar velocity fields in the local neighbourhood. Our reconstructed distances are well-matched to the observed values outside the collapsed regions if Omega_m(t)= 0.20 exp(-0.26 (t-13)) where t is the age of the Universe in Gyrs., Comment: 10 pages, 4 figures, Invited contribution to Colloquium Cosmology: facts and Problems, College de France, Paris 8-11, June 2004, Eds. J.V. Narlikar, J-.C. Pecker

The observed infall of galaxies into the Virgo Cluster puts strong constraints on the mass of the cluster. A non-parametric fully non-linear description of the infall can be made with orbit reconstructions based on Numerical Action Methods. The mass of the cluster is determined to be $1.2 \times 10^{15} M_{\odot}$. The mass-to-light ratio for the cluster is found to be seven times higher than the mean ratio found across the region within V=3000 km/s., Comment: 7 pages, 3 figures, version to appear in "Outskirt of Galaxy Clusters", the proceedings of IAU Colloquim No 195, 2004

A deep blind HI survey of the nearby spiral rich Ursa Major cluster has been performed with the VLA in parallel with a wide-field R-band imaging campaign of most VLA fields with the CFHT. The goal is to measure the slope of the HI mass function down to HI masses of 10^7 Msun as well as the slope of the faint-end of the luminosity function down to M(R)=-10. The VLA survey sampled 16% of the Ursa Major cluster volume. Both the HIMF and the LF in Ursa Major are nearly flat at their faint-ends. No free- floating HI clouds were detected., Comment: 7 pages, 3 figures. Contribution to the Guanajuato meeting "Mapping the Hidden Universe". To appear in PASP, 2000

We summarise results for the predicted density and peculiar velocity fields from the PSCz survey. We have used a generalisation of the Path Interchange Zeldovich Approximation to determine the velocity field; the most remarkable feature being a coherent large-scale flow along the baseline connecting the Local Supercluster, Centaurus and the Shapley Concentration. Comparison of the predicted and observed bulk flows gives a value of beta = 0.50+-0.1. We re-examine the PSCz dipole, with improved redshift completeness at low-latitudes and using PIZA to estimate real-space distances. We find the dipole to be stable between 80 and 180 hMpc, although there appears to be a significant contribution to the dipole around 200 hMpc. The overall misalignment with the CMB dipole remains at 20degrees. The implied value of beta is in the range 0.40-0.55 with statistical error +-0.1. We also present the density field and a preliminary dipole analysis from the almost completed Behind The Plane survey, which extends the PSCz to cover 93% of the sky including the proposed core of the Great Attractor. We find a density peak at (325,-5,3500km/s), about half as massive as Centaurus or Pavo-Indus, and forming part of a continuous filament linking them across the Plane. We also find evidence for a much larger `Greater Attractor' directly behind the GA, at a distance of 125 hMpc, and more massive than the Shapley concentration. At large distances the dipole direction is in much improved agreement with the CMB: at 250-300hMpc, the misalignment is only 5-10 degrees, though this depends on the incompleteness corrections made. The dipole amplitude implies a value for the parameter beta of 0.44+-0.1., Comment: 10 pages. To appear in 'The Hidden Universe', procs Guanajuarto conference 2/00, ASP Conference series, eds R.C. Kraan-Korteweg, P.A. Henning and H. Andernach

We present details of the Behind The Plane survey of IRAS galaxies, which extends the PSCz survey to cover the 93% of the sky with complete and reliable IRAS data from the Point Source Catalog. At low latitudes, our catalogue is not complete to 0.6Jy, but the incompleteness is physically understood and can be corrected for. IRAS galaxies at low latitudes are heavily or completely obscured optically, and are heavily outnumbered by Galactic sources with similar IRAS properties. We have used radio, optical, mm, near and far-infrared data to identify the galaxies, and the 2D catalogue is now complete. We have used optical and HI spectroscopy to obtain redshifts for the galaxies; the southern spectroscopy is completed and the north nearly so., Comment: 3 pages. To appear in 'The Hidden Universe', procs Guanajuarto conference 2/00. ASP Conference series, eds R.C. Kraan-Korteweg, P.A. Henning and H. Andernach

We discuss the design and current status of the CIZA survey, the first systematic X-ray search for clusters of galaxies in the Galactic plane region. So far, we have compiled a sample of more than 70 X-ray selected clusters at |b|<20 deg, 80% of which were previously unknown. Upon its completion the CIZA cluster catalogue will complement the existing galaxy surveys in the Galactic plane region and allow a fresh look at large-scale structure and local streaming motions., Comment: 2 pages, 1 figure. Poster paper presented at the "Large-Scale Structure in the X-ray Universe" conference, Santorini, September 1999

We have extended the PSCz to cover 93% of the sky, the practical limit for any catalogue based on the Point Source Catalog. The galaxy identifications are complete, and the core of the Great Attractor is quantitatively mapped for the first time. We discuss the likely effect of the increased sky coverage on the IRAS dipole., Comment: 4 pages, 3 figures. To be published in 'Towards an Understanding of Cosmic Flows of Large-Scale Structure', Victoria, July 1999, eds Courteau,S., Strauss,M., Willick,J., to be published by PASP

A complete sample of spiral galaxies in the Ursa Major cluster is imaged at various optical wavelengths and in the Near-Infrared K'-band. HI rotation curves were obtained for all gas rich systems. The Near-Infrared surface brightness distribution of disk galaxies turns out to be bimodal; galaxies avoid a domain around a face-on disk central surface brightness of 18.5 mag/arcsec^2. This bimodality is particularly striking when only the more isolated, non-interacting systems are considered. The Luminosity Function of the HSB family of galaxies is truncated well above the completion limit while the Luminosity Function of the LSB family is still sharply rising at our limiting magnitude. Near-Infrared mass-to-light ratios suggest that HSB galaxies are close to a kinematic maximum-disk situation while LSB galaxies are dark matter dominated at all radii. Assuming equal Near-Infrared mass-to-light ratios for both HSB and LSB systems, we find that the gap in the surface brightness distribution corresponds to a situation in which the baryonic mass is marginally self-gravitating. We finally conclude that the luminosity-line width relation is a fundamental correlation between the amount and distribution of dark matter mass and the total luminosity, regardless of how the luminous mass is distributed within the dark mater halo., Comment: Latex file generating 10 pages and 6 figures. Contribution to the proceedings of IAU Colloquium 171; "The Low Surface Brightness Universe", Cardiff, 5-10 July 1998

Space Interferometry Mission (SIM) will be used to obtain proper motions for a sample of 27 galaxies; the first proper motion measurements of galaxies beyond the satellite system of the Milky Way. SIM measurements lead to knowledge of the full 6-dimensional position and velocity vector of each galaxy. In conjunction with new gravitational flow models, the result will be the first total mass measurements of individual galaxies. The project, includes developnient of powerful theoretical methods for orbital calculations. This SIM study will lead to vastly improved determinations of individual galaxy masses, halo sizes, and the fractional contribution of dark matter. Astronomers have struggled to calculate the orbits of galaxies with only position and redshift information. Traditional N-body techniques are unsuitable for an analysis backward in time from a present distribution if any components of velocity or position are not very precisely known.

At Mauna Kea Observatory, researchers conducted optical, imaging spectrophotometric studies of selected active galaxies using both the Canada-France-Hawaii 3.6m and University of Hawaii 2.2m telecopes (Tully, Bland and Cecil 1988). To maximize spatial resolution, researchers select galaxies independent of luminosity but known to possess interesting morphologies or high-velocity, extranuclear ionized gas (Walker 1968; Rubin and Ford 1968). They study both the large-scale patterns produced in IR-luminous, starburst systems (e.g., M82, NGC 253, NGC 6240) and those with compact, but spatially extended, circumnuclear, narrow line regions (e.g., M51, NGC 1068, NGC 4151). Current studies are restricted to the optical (SII), (NII) and (OIII) lines and the brightest Balmer recombination lines. These lines are, in principle, sufficient to constrain the dynamical structure and dominant excitation mechanism of the ionized component.