Millimeter and submillimeter images of various galaxies in the universe.
Nearby galaxies †
M 83: a nearby barred spiral galaxy hosting a nuclear starburst †
- Velocity integrated intensity and intensity-weighted mean velocity images of CO(J=3-2) emission in the spiral galaxy M 83.
- Comparison of the CO(J=3-2) image with massive star formation tracers, H alpha (left) and 8 um (right).
M 51: a grand design spiral galaxy hosting a type-2 Seyfert nucleus †
- Kohno, K., Kawabe, R., Tosaki, T., and Okumura, K. S., 1996, ``Aperture Synthesis CO and HCN Observations of M51: Dense Molecular Disk around a Low-Luminosity Active Galactic Nucleus", ApJ, 461, L29-L32
- Matsushita, S., Kohno, K., Vila-Vilaro, B., Tosaki, T., and Kawabe, R., 1998, ``High-Density and High-Temperature Circumnuclear Molecular Disk in M51", ApJ, 495, 267-275
NGC 1097: a low luminosity AGN accompanied with intense circumnuclear starburst †
NGC 5033: a low luminosity AGN with little nuclear star-formation activity †
- CO(J=1-0) integrated intensity and intensity-weighted mean velocity images of the central part of NGC 5033. These images were taken with the Nobeyama Millimeter Array.
NGC 6951: a Seyfert nucleus in a strongly barred spiral galaxy with a starburst ring †
- Kohno, K., Kawabe, R., and Vila-Vilaro, B., 1999, ``Dense Molecular Gas Associated with the Circumnuclear Star Forming Ring in the Barred Spiral Galaxy NGC 6951", ApJ, 511, 157-177
NGC 5195: a barred, gas rich S0 galaxy without any signature for on-going star-formation at the nucleus †
M33: one of the nearest face-on spiral galaxies †
- We present a giant molecular cloud (GMC) catalog of M33, containing 71 GMCs in total, based on wide-field and high-sensitivity CO(J = 3-2) observations with a spatial resolution of 100 pc using the ASTE 10 m telescope.
- 1.1 mm continuum map superposed on H alpha emission.
- A map of cold dust temperature derived from the 1.1 mm to 160 um ratio.
- Komugi, S., Tosaki, T., Kohno, K., et al., 2011, PASJ, 63, 1139
- We present wide-field 1.1 mm continuum imaging of the nearby spiral galaxy M 33, conducted with the AzTEC bolometer camera on ASTE. We show that the 1.1 mm flux traces the distribution of dust with T ~20 K.
- Combined with far-infrared imaging at 160um, we derive the dust temperature distribution out to a galactic radius of ~7 kpc with a spatial resolution of ~100 parsecs. Although the 1.1 mm flux is observed predominantly near star forming regions, we find a smooth radial temperature gradient declining from ~20 K to ~13 K, consistent with recent results from the Herschel satellite.
- Further comparison of individual regions show a strong correlation between the cold dust temperature and the Ks band brightness, but not with the ionizing flux. The observed results imply that the dominant heating source of cold dust at few hundred parsec scales are due to the non-OB stars, even when associated with star forming regions.
Gamma-ray bursts †
GRB 030329: one of the brightest Gamma-ray bursts to date ("monster burst") at z = 0.1685 †
- Kohno et al., 2005, "Nobeyama Millimeter Array Observations of GRB 030329: a Decay of Afterglow with Bumps and Molecular Gas in the Host Galaxy", PASJ, 57, 147-153
- see also Endo, A., Kohno, K., Hatsukade, B., et al., 2007, ApJ, 659, 1431
GRB 020819B: first detection of the CO emission among the GRB host galaxies! †
- Spatially resolved CO(3-2) (left) and 1.2 mm continuum (middle) images taken with ALMA, along with an optical R-band image obtained using the Gemini-South Telescope (right) of GRB 020819B at z = 0.41 show that the burst happened in a dusty region with little molecular gas; the observed M(gas)/M(dust) ratio is less than 14, which is surprisingly low compared with typical star-forming galaxies (M(gas)/M(dust) ratios of ~50 - 100).
BR1202-0725, a radio quiet quasar at redshift of 4.7 †
CO(J=5-4) spectrum taken with the NMA.
CO(J=5-4) velocity-integrated intensity image of BR1202-0725.
- Ohta, K., Yamada, T., Nakanishi, K., Kohno, K., Akiyama, M., and Kawabe, R., 1996, ``Detection of molecular gas in the quasar BR 1202-0725 at redshift z = 4.69", Nature, 382, 426-428
(Sub)millimeter galaxies †
SSA22-AzTEC1: a proto-quasar at the center of the proto-cluster at z=3? †
- At the SMA position, we find radio-to-mid-infrared counterparts, whilst no object is found in Subaru optical and near-infrared deep images at wavelengths <=1 μm (J > 25.4 in AB, 2σ).
- It is possible that SSA22-AzTEC1 is the first example of a protoquasar growing at the bottom of the gravitational potential underlying the SSA22 protocluster.
Orochi (SXDF1100.1): an ultra-bright starburst galaxy at z=3.4 †
Deep surveys of submillimeter galaxies †
SSA22, a protocluster regioin traced by an overdensity of Lyman Alpha Emitters (LAEs) at redshift of 3.1. †
- Tamura, Y., Kohno, K., Nakanishi, K., Hatsukade, B., Iono, D., et al. 2009, Nature, 459, 61-63
- Figure 1. The positions of 1,100-mm sources and Lya emitters towards the
SSA 22 protocluster region.
- (a) The colour scale shows the map of signal-to-noise
ratio at 1100 um. The map shows 30 sources with signal-to-noise
ratios >3.5 (circles). Observations of SSA 22 (field centre at
RA 22h 17m 36s, dec. +0deg 15' 00'' (J2000)) were obtained using the
AzTEC camera, operating at 1100 um, mounted on the ASTE 10-m
submillimetre telescope during the July–September 2007 observing season.
The data consist of a total of 42 h of integration time on source under
excellent conditions (zenith atmospheric opacity at 220 GHz,
tau(220GHz) > 0.01–0.10). This resulted in a root-mean-square noise level of
0.68–0.99 mJy per beam over 390 arcmin^2. The point spread function of
AzTEC on ASTE has a full-width at half-maximum of 2861 arcsec.
- (b) The locations of the bright submillimetre galaxies with S(1100um) > 2.7 mJy (orange filled circles) and the Lya emitters at z~3.1 (white dots). The sizes of the orange circles are proportional to their 1100 mm fluxes. The number
density field of the Lya emitters is shown in the colour scale, highlighting the
density enhancement of the Lya emitters, which is thought to trace out the
underlying large-scale structure at z~3.1.
AKARI Deep Field South (ADF-S) 1.1 mm view †
- We present results of a 1.1-mm deep survey of the AKARI Deep Field South (ADF-S) with AzTEC mounted on the Atacama Submillimetre Telescope Experiment (ASTE). We obtained a map of 0.25-deg2 area with an rms noise level of 0.32-0.71 mJy. This is one of the deepest and widest maps thus far at millimetre and submillimetre wavelengths.
- We uncovered 198 sources with a significance of 3.5σ-15.6σ, providing the largest catalogue of 1.1-mm sources in a contiguous region. Most of the sources are not detected in the far-infrared bands of the AKARI satellite, suggesting that they are mostly at z≥ 1.5 given the detection limits.