G. Kosugi - Academia.edu (original) (raw)

Papers by G. Kosugi

International Astronomical Union Colloquium

We developed a slit-scanning type 3D-spectroscopic system named as Spectronebulagraph (hereafter ... more We developed a slit-scanning type 3D-spectroscopic system named as Spectronebulagraph (hereafter SNG; Kosugi et al. 1994) at Okayama Astrophysical Observatory. A detailed description about SNG is presented by Ohtani et al. elsewhere in this colloquium. We present here the results of the 3D-spectroscopy of four nearby active galaxies by using SNG.This nearby (at distance of 5.4 Mpc) Magellanic irregular galaxy has many H II regions in its main body suggesting violent star-formation activity. We performed tridimensional observations of NGC 4449 using SNG in order to obtain detailed kinematic structure and then to investigate the star-formation mechanism of NGC 4449. Hα intensity map, Hα velocity field are shown in figure 1. As is obvious in lower panel of figure 1, no global rotational motion was detected. Most impressive feature of the velocity field is kpc-scale mosaic structure of low velocity and high velocity components. Also, many filamentary components were newly found in 3D-da...

International Astronomical Union Colloquium

The researches into extended emission line region (EELR) give us the valuable informations about ... more The researches into extended emission line region (EELR) give us the valuable informations about the nucleus. A recent study of the EELR in the Seyfert 1 galaxy NGC 4151 by Yoshida and Ohtani (1993) have revealed that a strongly asymmetric radiation field in this typical Seyfert 1. They have suggested the anisotropy may be caused inside the BLR. It is important to examine if any other Seyfert 1 galaxy has an anisotropic nuclear radiation.The famous Seyfert 1 galaxy NGC 3516 has EELR which extends ∼ 10” on either side of the nucleus. The morphology of the EELR is Z-shape. This nearby (D=38.9Mpc) galaxy is of type SBO for which the object is expected to be free from contamination by HII regions and dust clouds.

Symposium - International Astronomical Union

Aoki et al. (1996) found outflowing gas in the Seyfert galaxy NGC 7319. The velocity of the outfl... more Aoki et al. (1996) found outflowing gas in the Seyfert galaxy NGC 7319. The velocity of the outflow comes up to 500 km s−1 and its extent is 4 kpc. This outflow is one of the largest outflowing phenomenon that have ever been found in Seyfert galaxies. The radio emission found by van der Hulst & Rots (1981) aligns the outflowing gas. It suggests the radio emission has relation to the outflow. We have made higher resolution radio imaging of NGC 7319 with VLA to study in detail relation of radio emission to outflowing gas. These radio images have been compared to Hubble Space Telescope (HST) archival broad-band WFPC2 image. The systemic velocity 6740 km s−1 (Aoki et al. 1996) gives a distance of 90 Mpc for NGC 7319 assuming a Hubble constant H0=75 km s−1 Mpc−1. Thus 1″ corresponds to 450 pc.

International Astronomical Union Colloquium

NGC 1275, the Perseus cluster cD galaxy, is a well-known Seyfert 1 galaxy and also one of the str... more NGC 1275, the Perseus cluster cD galaxy, is a well-known Seyfert 1 galaxy and also one of the strongest extragalactic radio sources (3C84). Although many studies have been done on the extended optical emission-line region of NGC 1275, which is thought to be associated with the X-ray cooling-flow phenomenon (e.g., Heckman et al. 1989, Ferruit and Pecontal 1994), the excitation mechanism of the emission-line gas and two-dimensional gas kinematics are still unclear. We made tri-dimensional spectroscopy of NGC 1275 in order to reveal two-dimensional kinematics and- the relation between the gas motion and the excitation of the emission lines.

The control system for the SUBARU telescope is designed to consist of distributed workstations, l... more The control system for the SUBARU telescope is designed to consist of distributed workstations, local processors, and data acquisition computers, which are interconnected by control LANs and data LANs. The control software achieves its functionality with message-based communication. Two key processes, a scheduler and a status logger cooperating with any other processes, are designed to perform efficiency and security in

A 60 cm Ritchey-Chrétien optical system has been manufactured and installed in the tube of the 40... more A 60 cm Ritchey-Chrétien optical system has been manufactured and installed in the tube of the 40 cm Schmidt telescope in replacement of the Schmidt optical system. The mirror systerm is described together with the correcting lens. Descriptions are also given for observation instruments, i.e., a photographic camera, a CCD camera, spectronebulagraph, and a multi-object photoelectric photometer.

IAUC 8119 available at Central Bureau for Astronomical Telegrams.

Publications of the Astronomical Society of Japan, 2001

Deep near-infrared images of a blank 2 × 2 section of sky near the galactic north pole taken by S... more Deep near-infrared images of a blank 2 × 2 section of sky near the galactic north pole taken by Subaru Telescope are presented. The total integration times of the J and K bands were 12.1 hr and 9.7 hr, resulting in 5 σ limiting magnitudes of 25.1 and 23.5 mag, respectively. The numbers of sources within these limiting magnitudes found with an automated detection procedure are 385 in the J band and 350 in K. Based on photometric measurements of these sources, we present number count vs. magnitude relations, color vs. magnitude diagrams, size vs. color relationships, etc. The slope of the galaxy number count plotted against the AB magnitude scale is about 0.23 in the 22 to 26 AB magnitude range of both bands. The spatial number density of galaxies as well as the slopes in the faint-end region given by the Subaru Deep Field (SDF) survey are consistent with those given by HST-NICMOS surveys, as expressed on the AB magnitude diagram. Several sources having very large J − K color have been found, including a few K objects without detection at J. In addition, a number of faint galactic stars were also detected, most of which are assigned to M-subdwarfs, together with a few brown dwarf candidates.

In order to support observations made with the Subaru Telescope located atop Mauna Kea, Hawaii, a... more In order to support observations made with the Subaru Telescope located atop Mauna Kea, Hawaii, a synthesized software system has been developed in the past several years. It consists of the Subaru Observation Software System, the Subaru Telescope Archive System, and the Data Analysis System Hierarchy. This was a challenging project of the Japanese astronomical community and it contributes to the operational data flow and quality control of observational data of the Subaru Telescope.

We present multi-waveband optical imaging data of the Subaru/ XMM-Newton Deep Survey (SXDS). The ... more We present multi-waveband optical imaging data of the Subaru/ XMM-Newton Deep Survey (SXDS). The SXDS has been the focus of wide range of multi-wavelength observing programs spanning the X-ray to the radio. The optical imaging observations are carried out with Suprime-Cam in the course of Subaru Telescope "Observatory Projects". A total area of 1.22 square degree is covered in five contiguous sub-fields, each of which corresponds to a single Suprime-Cam field of view (34'× 27'), in five broadband filters to the depths of B=28.4, V=27.8, R_c=27.7, i'=27.7, and z'=26.6 (AB, 3-sigma, phi-2arcsec). The data are reduced and compiled into five multi-waveband photometric catalogs, separately for each Suprime-Cam field. The i'-band catalogs contain about 900,000 objects in total, making the SXDS catalogs one of the largest multi-waveband object catalogs in corresponding depth and area coverage. The SXDS catalogs can be used for an extensive range of astronomica...

The Astrophysical Journal, 2015

A major goal of the Atacama Large Millimeter/submillimeter Array (ALMA) is to make accurate image... more A major goal of the Atacama Large Millimeter/submillimeter Array (ALMA) is to make accurate images with resolutions of tens of milliarcseconds, which at submillimeter (submm) wavelengths requires baselines up to ∼15 km. To develop and test this capability, a Long Baseline Campaign (LBC) was carried out from September to late November 2014, culminating in end-to-end observations, calibrations, and imaging of selected Science Verification (SV) targets. This paper presents an overview of the campaign and its main results, including an investigation of the short-term coherence properties and systematic phase errors over the long baselines at the ALMA site, a summary of the SV targets and observations, and recommendations for science observing strategies at long baselines. Deep ALMA images of the quasar 3C138 at 97 and 241 GHz are also compared to VLA 43 GHz results, demonstrating an agreement at a level of a few percent. As a result of the extensive program of LBC testing, the highly successful SV imaging at long baselines achieved angular resolutions as fine as 19 mas at ∼350 GHz. Observing with ALMA on baselines of up to 15 km is now possible, and opens up new parameter space for submm astronomy.

Publications of the Astronomical Society of Japan, 2002

The Faint Object Camera and Spectrograph (FOCAS) is a Cassegrain optical instrument for the Subar... more The Faint Object Camera and Spectrograph (FOCAS) is a Cassegrain optical instrument for the Subaru Telescope. Its capabilities include 6 φ FOV direct imaging, low-resolution spectroscopy (R = 250-2000 with 0. 4 slitwidth), multi-slit spectroscopy and polarimetry. We describe the overall design of FOCAS, its observing functions, and the performance verification procedures that have been carried out.

Publications of the Astronomical Society of Japan, 2001

High-resolution near-infrared (J H KL M) images of a massive star-forming region, S 255-2, were o... more High-resolution near-infrared (J H KL M) images of a massive star-forming region, S 255-2, were obtained with the Subaru Telescope and an infrared camera, CIAO. These images clearly resolve two sets of bipolar nebulae illuminated by two independent massive YSOs. A number of cluster member YSOs have been detected, including 3 new sources. Seven early-B type stars have been identified within 10 pc of S 255-2; three are associated with extended optical H II regions. The variation in the appearance of these early-B type stars suggests an evolutionary sequence of massive stars in the S 255 region.

Software and Cyberinfrastructure for Astronomy II, 2012

ABSTRACT At the end of 2012, ALMA software development will be completed. While new releases are ... more ABSTRACT At the end of 2012, ALMA software development will be completed. While new releases are still being prepared following an incremental development process, the ALMA software has been in daily use since 2008. Last year it was successfully used for the first science observations proposed by and released to the ALMA scientific community. This included the whole project life cycle from proposal preparation to data delivery, taking advantage of the software being designed as an end-to-end system. This presentation will report on software management aspects that became relevant in the last couple of years. These include a new feature driven development cycle, an improved software verification process, and a more realistic test environment at the observatory. It will also present a forward look at the planned transition to full operations, given that upgrades, optimizations and maintenance will continue for a long time.

Software and Cyberinfrastructure for Astronomy, 2010

ABSTRACT The ALMA Software (~ 80% completed) is in daily use at the ALMA Observatory and has been... more ABSTRACT The ALMA Software (~ 80% completed) is in daily use at the ALMA Observatory and has been developed as an end-toend system including: proposal preparation, dynamic scheduling, instrument control, data handling and formatting, data archiving and retrieval, automatic and manual data processing, and support for observatory operations. This presentation will expand on some software management aspects, procedures for releases, integrated system testing and deployment in Chile. The need for a realistic validation environment, now achieved with a two antenna interferometer at the observatory, and the balance between incremental development and stability of the software (a challenge at the moment) will be explained.

International Astronomical Union Colloquium

We developed a slit-scanning type 3D-spectroscopic system named as Spectronebulagraph (hereafter ... more We developed a slit-scanning type 3D-spectroscopic system named as Spectronebulagraph (hereafter SNG; Kosugi et al. 1994) at Okayama Astrophysical Observatory. A detailed description about SNG is presented by Ohtani et al. elsewhere in this colloquium. We present here the results of the 3D-spectroscopy of four nearby active galaxies by using SNG.This nearby (at distance of 5.4 Mpc) Magellanic irregular galaxy has many H II regions in its main body suggesting violent star-formation activity. We performed tridimensional observations of NGC 4449 using SNG in order to obtain detailed kinematic structure and then to investigate the star-formation mechanism of NGC 4449. Hα intensity map, Hα velocity field are shown in figure 1. As is obvious in lower panel of figure 1, no global rotational motion was detected. Most impressive feature of the velocity field is kpc-scale mosaic structure of low velocity and high velocity components. Also, many filamentary components were newly found in 3D-da...

International Astronomical Union Colloquium

The researches into extended emission line region (EELR) give us the valuable informations about ... more The researches into extended emission line region (EELR) give us the valuable informations about the nucleus. A recent study of the EELR in the Seyfert 1 galaxy NGC 4151 by Yoshida and Ohtani (1993) have revealed that a strongly asymmetric radiation field in this typical Seyfert 1. They have suggested the anisotropy may be caused inside the BLR. It is important to examine if any other Seyfert 1 galaxy has an anisotropic nuclear radiation.The famous Seyfert 1 galaxy NGC 3516 has EELR which extends ∼ 10” on either side of the nucleus. The morphology of the EELR is Z-shape. This nearby (D=38.9Mpc) galaxy is of type SBO for which the object is expected to be free from contamination by HII regions and dust clouds.

Symposium - International Astronomical Union

Aoki et al. (1996) found outflowing gas in the Seyfert galaxy NGC 7319. The velocity of the outfl... more Aoki et al. (1996) found outflowing gas in the Seyfert galaxy NGC 7319. The velocity of the outflow comes up to 500 km s−1 and its extent is 4 kpc. This outflow is one of the largest outflowing phenomenon that have ever been found in Seyfert galaxies. The radio emission found by van der Hulst & Rots (1981) aligns the outflowing gas. It suggests the radio emission has relation to the outflow. We have made higher resolution radio imaging of NGC 7319 with VLA to study in detail relation of radio emission to outflowing gas. These radio images have been compared to Hubble Space Telescope (HST) archival broad-band WFPC2 image. The systemic velocity 6740 km s−1 (Aoki et al. 1996) gives a distance of 90 Mpc for NGC 7319 assuming a Hubble constant H0=75 km s−1 Mpc−1. Thus 1″ corresponds to 450 pc.

International Astronomical Union Colloquium

NGC 1275, the Perseus cluster cD galaxy, is a well-known Seyfert 1 galaxy and also one of the str... more NGC 1275, the Perseus cluster cD galaxy, is a well-known Seyfert 1 galaxy and also one of the strongest extragalactic radio sources (3C84). Although many studies have been done on the extended optical emission-line region of NGC 1275, which is thought to be associated with the X-ray cooling-flow phenomenon (e.g., Heckman et al. 1989, Ferruit and Pecontal 1994), the excitation mechanism of the emission-line gas and two-dimensional gas kinematics are still unclear. We made tri-dimensional spectroscopy of NGC 1275 in order to reveal two-dimensional kinematics and- the relation between the gas motion and the excitation of the emission lines.

The control system for the SUBARU telescope is designed to consist of distributed workstations, l... more The control system for the SUBARU telescope is designed to consist of distributed workstations, local processors, and data acquisition computers, which are interconnected by control LANs and data LANs. The control software achieves its functionality with message-based communication. Two key processes, a scheduler and a status logger cooperating with any other processes, are designed to perform efficiency and security in

A 60 cm Ritchey-Chrétien optical system has been manufactured and installed in the tube of the 40... more A 60 cm Ritchey-Chrétien optical system has been manufactured and installed in the tube of the 40 cm Schmidt telescope in replacement of the Schmidt optical system. The mirror systerm is described together with the correcting lens. Descriptions are also given for observation instruments, i.e., a photographic camera, a CCD camera, spectronebulagraph, and a multi-object photoelectric photometer.

IAUC 8119 available at Central Bureau for Astronomical Telegrams.

Publications of the Astronomical Society of Japan, 2001

Deep near-infrared images of a blank 2 × 2 section of sky near the galactic north pole taken by S... more Deep near-infrared images of a blank 2 × 2 section of sky near the galactic north pole taken by Subaru Telescope are presented. The total integration times of the J and K bands were 12.1 hr and 9.7 hr, resulting in 5 σ limiting magnitudes of 25.1 and 23.5 mag, respectively. The numbers of sources within these limiting magnitudes found with an automated detection procedure are 385 in the J band and 350 in K. Based on photometric measurements of these sources, we present number count vs. magnitude relations, color vs. magnitude diagrams, size vs. color relationships, etc. The slope of the galaxy number count plotted against the AB magnitude scale is about 0.23 in the 22 to 26 AB magnitude range of both bands. The spatial number density of galaxies as well as the slopes in the faint-end region given by the Subaru Deep Field (SDF) survey are consistent with those given by HST-NICMOS surveys, as expressed on the AB magnitude diagram. Several sources having very large J − K color have been found, including a few K objects without detection at J. In addition, a number of faint galactic stars were also detected, most of which are assigned to M-subdwarfs, together with a few brown dwarf candidates.

In order to support observations made with the Subaru Telescope located atop Mauna Kea, Hawaii, a... more In order to support observations made with the Subaru Telescope located atop Mauna Kea, Hawaii, a synthesized software system has been developed in the past several years. It consists of the Subaru Observation Software System, the Subaru Telescope Archive System, and the Data Analysis System Hierarchy. This was a challenging project of the Japanese astronomical community and it contributes to the operational data flow and quality control of observational data of the Subaru Telescope.

We present multi-waveband optical imaging data of the Subaru/ XMM-Newton Deep Survey (SXDS). The ... more We present multi-waveband optical imaging data of the Subaru/ XMM-Newton Deep Survey (SXDS). The SXDS has been the focus of wide range of multi-wavelength observing programs spanning the X-ray to the radio. The optical imaging observations are carried out with Suprime-Cam in the course of Subaru Telescope "Observatory Projects". A total area of 1.22 square degree is covered in five contiguous sub-fields, each of which corresponds to a single Suprime-Cam field of view (34'× 27'), in five broadband filters to the depths of B=28.4, V=27.8, R_c=27.7, i'=27.7, and z'=26.6 (AB, 3-sigma, phi-2arcsec). The data are reduced and compiled into five multi-waveband photometric catalogs, separately for each Suprime-Cam field. The i'-band catalogs contain about 900,000 objects in total, making the SXDS catalogs one of the largest multi-waveband object catalogs in corresponding depth and area coverage. The SXDS catalogs can be used for an extensive range of astronomica...

The Astrophysical Journal, 2015

A major goal of the Atacama Large Millimeter/submillimeter Array (ALMA) is to make accurate image... more A major goal of the Atacama Large Millimeter/submillimeter Array (ALMA) is to make accurate images with resolutions of tens of milliarcseconds, which at submillimeter (submm) wavelengths requires baselines up to ∼15 km. To develop and test this capability, a Long Baseline Campaign (LBC) was carried out from September to late November 2014, culminating in end-to-end observations, calibrations, and imaging of selected Science Verification (SV) targets. This paper presents an overview of the campaign and its main results, including an investigation of the short-term coherence properties and systematic phase errors over the long baselines at the ALMA site, a summary of the SV targets and observations, and recommendations for science observing strategies at long baselines. Deep ALMA images of the quasar 3C138 at 97 and 241 GHz are also compared to VLA 43 GHz results, demonstrating an agreement at a level of a few percent. As a result of the extensive program of LBC testing, the highly successful SV imaging at long baselines achieved angular resolutions as fine as 19 mas at ∼350 GHz. Observing with ALMA on baselines of up to 15 km is now possible, and opens up new parameter space for submm astronomy.

Publications of the Astronomical Society of Japan, 2002

The Faint Object Camera and Spectrograph (FOCAS) is a Cassegrain optical instrument for the Subar... more The Faint Object Camera and Spectrograph (FOCAS) is a Cassegrain optical instrument for the Subaru Telescope. Its capabilities include 6 φ FOV direct imaging, low-resolution spectroscopy (R = 250-2000 with 0. 4 slitwidth), multi-slit spectroscopy and polarimetry. We describe the overall design of FOCAS, its observing functions, and the performance verification procedures that have been carried out.

Publications of the Astronomical Society of Japan, 2001

High-resolution near-infrared (J H KL M) images of a massive star-forming region, S 255-2, were o... more High-resolution near-infrared (J H KL M) images of a massive star-forming region, S 255-2, were obtained with the Subaru Telescope and an infrared camera, CIAO. These images clearly resolve two sets of bipolar nebulae illuminated by two independent massive YSOs. A number of cluster member YSOs have been detected, including 3 new sources. Seven early-B type stars have been identified within 10 pc of S 255-2; three are associated with extended optical H II regions. The variation in the appearance of these early-B type stars suggests an evolutionary sequence of massive stars in the S 255 region.

Software and Cyberinfrastructure for Astronomy II, 2012

ABSTRACT At the end of 2012, ALMA software development will be completed. While new releases are ... more ABSTRACT At the end of 2012, ALMA software development will be completed. While new releases are still being prepared following an incremental development process, the ALMA software has been in daily use since 2008. Last year it was successfully used for the first science observations proposed by and released to the ALMA scientific community. This included the whole project life cycle from proposal preparation to data delivery, taking advantage of the software being designed as an end-to-end system. This presentation will report on software management aspects that became relevant in the last couple of years. These include a new feature driven development cycle, an improved software verification process, and a more realistic test environment at the observatory. It will also present a forward look at the planned transition to full operations, given that upgrades, optimizations and maintenance will continue for a long time.

Software and Cyberinfrastructure for Astronomy, 2010

ABSTRACT The ALMA Software (~ 80% completed) is in daily use at the ALMA Observatory and has been... more ABSTRACT The ALMA Software (~ 80% completed) is in daily use at the ALMA Observatory and has been developed as an end-toend system including: proposal preparation, dynamic scheduling, instrument control, data handling and formatting, data archiving and retrieval, automatic and manual data processing, and support for observatory operations. This presentation will expand on some software management aspects, procedures for releases, integrated system testing and deployment in Chile. The need for a realistic validation environment, now achieved with a two antenna interferometer at the observatory, and the balance between incremental development and stability of the software (a challenge at the moment) will be explained.