Shoko Sakai

Dwarf Galaxy Starburst Statistics in the Local Volume (2008)

Lee, Janice C., Kennicutt Jr., Robert C., Sakai, Shoko, Akiyama, Sanae

An unresolved question in galaxy evolution is whether the star formation histories of low mass systems are preferentially dominated by starbursts or modes that are more quiescent and continuous....

The Extragalactic Distance Scale without Cepheids (2008)

Mould, Jeremy, Sakai, Shoko

Distances of galaxies in the Hubble Space Telescope Key Project are based on the Cepheid period-luminosity relation. An alternative basis is the tip of the red giant branch. Using archival HST data,...

An H-alpha Imaging Survey of Galaxies in the Local 11 Mpc Volume (2008)

Kennicutt Jr., Robert C., Lee, Janice C., Sakai, Shoko, Akiyama, Sanae

As part of a broader effort to characterize the population of star-forming galaxies in the local universe, we have carried out an H-alpha+[NII] imaging survey for an essentially volume-limited sample...

The Star Formation Demographics of Galaxies in the Local Volume (2007)

Lee, Janice C., Kennicutt, Robert C., Funes, Jose G., Sakai, Shoko, Akiyama, Sanae

We examine the connections between the current global star formation activity, luminosity, dynamical mass and morphology of galaxies in the Local Volume, using H-alpha data from the 11 Mpc H-alpha...

Tip of the Red Giant Branch Distances. II. Zero-Point Calibration (2007)

Rizzi, Luca, Tully, R. Brent, Makarov, Dmitry, Makarova, Lidia, Dolphin, Andrew E., Sakai, Shoko, ...

The luminosity of the Tip of the Red Giant Branch (TRGB) provides an excellent measure of galaxy distances and is easily determined in the resolved images of nearby galaxies observed with Hubble...

Tip of the Red Giant Branch Distances. I. Optimization of a Maximum Likelihood Algorithm (2006)

Makarov, Dmitry, Makarova, Lidia, Rizzi, Luca, Tully, R. Brent, Dolphin, Andrew E., Sakai, Shoko, ...

Accurate distances to galaxies can be determined from the luminosities of stars at the Tip of the Red Giant Branch (TRGB). We use a Maximum Likelihood algorithm to locate the TRGB in galaxy...

The HST Key Project on the Extragalactic Distance Scale VI. The Cepheids in NGC925 (2004)

Silbermann, N. A., Harding, Paul, Madore, Barry F., Kennicutt, Robert C. Jr., Saha, Abhijit, Stetson, Peter, ...

We report the detection of Cepheid Variable stars in the barred spiral galaxy NGC925, using the Hubble Space Telescope (HST) Wide Field and Planetary Camera 2 (WFPC2). Twelve V (F555W), four I...

Detection of the Tip of the Red Giant Branch in NGC 3379 (M105) in the Leo I Group (Draft 3/11/96) (2004)

Sakai, Shoko, Madore, Barry F., Freedman, Wendy L., Lauer, Tod R., Ajhar, Edward A., Baum, William A.

We report the unambiguous detection of individually resolved stars in the elliptical galaxy NGC 3379, a luminous member of the Leo I Group.

Calibration of the Extragalactic Distance Scale: Tip of the Red Giant Branch Distance to NGC 3379 (M105) in the Leo I Group (2004)

Sakai, Shoko, Madore, Barry F., Freedman, Wendy L., Lauer, Tod

We report the unambiguous detection of individually resolved stars in the elliptical galaxy NGC 3379, a luminous member of the Leo I Group.

The Effect of Metallicity on Cepheid-Based Distances (2004)

Sakai, Shoko, Ferrarese, Laura, Kennicutt, Rob, Saha, Abi

We have used the Wide Field and Planetary Camera 2 on board the Hubble Space Telescope to obtain V and I images of seven nearby galaxies. For each, we have measured a distance using the tip of the...

Discovery of a Group of Star-Forming Dwarf Galaxies in Abell 1367 (2002)

Sakai, Shoko, Kennicutt, Robert, Van Der Hulst, J. M., Moss, Chris

We describe the properties of a remarkable group of actively star-forming dwarf galaxies and HII galaxies in the Abell 1367 cluster, which were discovered in a large-scale H-alpha imaging survey of...

Redshifts for 2410 Galaxies in the Century Survey Region (2001)

Wegner, G., Thorstensen, J. R., Kurtz, M. J., Brown, W. R., Fabricant, D. G., Geller, M. J., ...

The `Century Survey' strip covers 102 square degrees within the limits 8.5h \leq \alpha_{1950} \leq 16.5h, 29.0 degrees \leq \delta_{1950} \leq 30.0 degrees. The strip passes through the Corona...

Six-Year Population Fluctuation of the Giant Honey Bee Apis dorsata (Hymenoptera: Apidae) in a Tropical Lowland Dipterocarp Forest in Sarawak (2001)

Takao Itioka, Tamiji Inoue, Het Kaliang, Makoto Kato, Teruyoshi Nagamitsu, Kuniyasu Momose, ...

The giant honey bee Apis dorsata F. inhabits lowland tropical rainforests in Southeast Asia, where a general, community-wide flowering occurs at intervals of 4 yr on average. The numerical response...

Observation of the Halo of NGC 3077 Near the "Garland" Region Using the Hubble Space Telescope (2001)

Sakai, Shoko, Madore, Barry

We report the detection of upper main sequence stars and red giant branch stars in the halo of an amorphous galaxy, NGC3077. The observations were made using Wide Field Planetary Camera~2 on board...

Final results from the Hubble Space Telescope key project to measure the Hubble Constant (2001)

Freedman, Wendy L., Madore, Barry F., Gibson, Brad K., Ferrarese, Laura, Kelson, Daniel D., Sakai, Shoko, ...

We present here the final results of the Hubble Space Telescope (HST) Key Project to measure the Hubble constant. We summarize our method, the results, and the uncertainties, tabulate our revised...

Final results from the Hubble Space Telescope key project to measure the Hubble Constant (2001)

Freedman, Wendy L., Madore, Barry F., Gibson, Brad K., Ferrarese, Laura, Kelson, Daniel D., Sakai, Shoko, ...

We present here the final results of the Hubble Space Telescope (HST) Key Project to measure the Hubble constant. We summarize our method, the results, and the uncertainties, tabulate our revised...

Final results from the Hubble Space Telescope key project to measure the Hubble Constant (2001)

Freedman, Wendy L., Madore, Barry F., Gibson, Brad K., Ferrarese, Laura, Kelson, Daniel D., Sakai, Shoko, ...

We present here the final results of the Hubble Space Telescope (HST) Key Project to measure the Hubble constant. We summarize our method, the results, and the uncertainties, tabulate our revised...

Final results from the Hubble Space Telescope key project to measure the Hubble Constant (2001)

Freedman, Wendy L., Madore, Barry F., Gibson, Brad K., Ferrarese, Laura, Kelson, Daniel D., Sakai, Shoko, ...

We present here the final results of the Hubble Space Telescope (HST) Key Project to measure the Hubble constant. We summarize our method, the results, and the uncertainties, tabulate our revised...

A Deep, Wide-Field H-alpha Survey of Nearby Clusters of Galaxies (2000)

Sakai, Shoko, Kennicutt, Robert, Moss, Chris

We present a progress report on an ongoing H-alpha imaging survey of nearby clusters of galaxies. Four clusters have been surveyed to date: A1367, A1656, A347 and A569. A preliminary comparison of...

Has Blending Compromised Cepheid-Based Determinations of the Extragalactic Distance Scale? (1999)

Gibson, Brad K., Maloney, Philip R., Sakai, Shoko

We examine the suggestion that half of the HST Key Project- and Sandage/Saha-observed galaxies have had their distances systematically underestimated, by 0.1-0.3 mag in the distance modulus, due to...

The Tip of the Red Giant Branch Distance to the Large Magellanic Cloud (1999)

Sakai, Shoko, Zaritsky, Dennis, Kennicutt, Robert

We present the I-band luminosity function of the red giant branch stars in the Large Magellanic Cloud (LMC) using the data from the Magellanic Clouds Photometric Survey (Zaritsky, Harris & Thompson,...

A Database of Cepheid Distance Moduli and TRGB, GCLF, PNLF and SBF Data Useful for Distance Determinations (1999)

Ferrarese, Laura, Ford, Holland C., Huchra, John, Kennicutt, Robert C., Mould, Jeremy R., ...

We present a compilation of Cepheid distance moduli and data for four secondary distance indicators that employ stars in the old stellar populations: the planetary nebula luminosity function (PNLF),...

The HST Key Project on the Extragalactic Distance Scale. XXVIII. Combining the Constraints on the Hubble Constant (1999)

Mould, Jeremy R, Huchra, John P, Freedman, Wendy L, Kennicutt Jr, Robert C, Ferrarese, Laura, Ford, Holland C, ...

Since the launch of the Hubble Space Telescope nine years ago, Cepheid distances to 25 galaxies have been determined for the purpose of calibrating secondary distance indicators. A variety of these...

The Hubble Space Telescope Key Project on the Extragalactic Distance Scale XXIV: The Calibration of Tully-Fisher Relations and the Value of the Hubble Constant (1999)

Sakai, Shoko, Mould, Jeremy R., Hughes, Shaun M. G., Huchra, John P., Macri, Lucas M., Kennicutt, Robert C., ...

This paper presents the calibration of BVRIH$ Tully-Fisher relations based on Cepheid distances to 21 galaxies within 25 Mpc, and 23 clusters within 10,000 km/s. These relations have been applied to...

The Extragalactic Distance Scale Key Project XXVII. A Derivation of the Hubble Constant Using the Fundamental Plane and Dn-Sigma Relations in Leo I, Virgo, and Fornax (1999)

Kelson, Daniel D., Illingworth, Garth D., Tonry, John L., Freedman, Wendy L., Kennicutt, Robert C., ...

Using published photometry and spectroscopy, we construct the fundamental plane and D_n-Sigma relations in Leo I, Virgo and Fornax. The published Cepheid P-L relations to spirals in these clusters...

The Hubble Constant from the HST Key Project on the Extragalactic Distance Scale (1999)

Ferrarese, Laura, Gibson, Brad, Kelson, Daniel, Sakai, Shoko, Mould, Jeremy, Freedman, Wendy, ...

The final efforts of the HST Key Project on the Extragalactic Distance Scale are presented. Four distance indicators, the Surface Brightness Fluctuation method, the Fundamental Plane for early-type...

The HST Key Project on the Extragalactic Distance Scale XXVI. The Calibration of Population II Secondary Distance Indicators and the Value of the Hubble Constant (1999)

Ferrarese, Laura, Mould, Jeremy R., Kennicutt, Robert C., Huchra, John, Ford, Holland C., ...

A Cepheid-based calibration is derived for four distance indicators that utilize stars in the old stellar populations: the tip of the red giant branch (TRGB), the planetary nebula luminosity function...

The HST Key Project on the Extragalactic Distance Scale XXV. A Recalibration of Cepheid Distances to Type Ia Supernovae and the Value of the Hubble Constant (1999)

Gibson, Brad K., Stetson, Peter B., Freedman, Wendy L., Mould, Jeremy R., Kennicutt, Robert C., ...

Cepheid-based distances to seven Type Ia supernovae (SNe)-host galaxies have been derived using the standard HST Key Project on the Extragalactic Distance Scale pipeline. For the first time, this...

Detection of the Red Giant Branch Stars in M82 Using the Hubble Space Telescope (1999)

Sakai, Shoko, Madore, Barry

We present color-magnitude diagrams and luminosity functions of stars in two halo regions of the irregular galaxy in M82, based on F555W and F814W photometry taken with the Hubble Space Telescope and...

The HST Key Project on the Extragalactic Distance Scale. XXII. The Discovery of Cepheids in NGC 1326-A (1999)

Prosser, Charles F., Kennicutt, Robert C., Bresolin, Fabio, Saha, Abhijit, Sakai, Shoko, ...

We report on the detection of Cepheids and the first distance measurement to the spiral galaxy NGC 1326-A, a member of the Fornax cluster of galaxies. We have employed data obtained with the Wide...

The Hubble Space Telescope Extragalactic Distance Scale Key Project XXIII. The Discovery of Cepheids In NGC 3319 (1999)

Sakai, Shoko, Ferrarese, Laura, Kennicutt, Robert C., Graham, John A., Silbermann, N. A., Mould, Jeremy R., ...

The distance to NGC 3319 has been determined from Cepheid variable stars as part of the Hubble Space Telescope Key Project on the Extragalactic Distance Scale. Thirteen and four epochs of...

The Extragalactic Distance Scale Key Project VIII. The Discovery of Cepheids and a New Distance to NGC3621 Using the Hubble Space Telescope (1999)

Daya M. Rawson, Lucas M. Macri, Jeremy R. Mould, John P. Huchra, Wendy L. Freedman, Robert C. Kennicutt, ...

We report on the discovery of Cepheids in the field spiral galaxy NGC 3621, based on observations made with the Wide Field and Planetary Camera 2 on board the Hubble Space Telescope (HST). NGC 3621...

The HST Key Project on the Extragalactic Distance Scale. XV. A Cepheid Distance to the Fornax Cluster and Its Implications (1998)

Madore, Barry F., Freedman, Wendy L., Silbermann, N., Harding, Paul, Huchra, John, Mould, Jeremy, ...

Using the Hubble Space Telescope (HST) 37 long-period Cepheid variables have been discovered in the Fornax Cluster spiral galaxy NGC 1365. The resulting V and I period-luminosity relations yield a...

The HST Key Project on the Extragalactic Distance Scale XVII. The Cepheid Distance to NGC 4725 (1998)

Gibson, Brad K., Hughes, Shaun M. G., Stetson, Peter B., Freedman, Wendy L., Kennicutt, Robert C., ...

The distance to NGC 4725 has been derived from Cepheid variables, as part of the Hubble Space Telescope Key Project on the Extragalactic Distance Scale. Thirteen F555W (V) and four F814W (I) epochs...

Cepheid and Tip of the Red Giant Branch Distances To the Dwarf Irregular Galaxy IC10 (1998)

Sakai, Shoko, Madore, Barry F., Freedman, Wendy L.

We present color-magnitude diagrams and luminosity functions of stars in the nearby galaxy IC 10, based on VI CCD photometry acquired with the COSMIC prime-focus camera on the Palomar 5m telescope....

The HST Key Project on the Extragalactic Distance Scale XII. The Discovery of Cepheids and a New Distance to NGC 2541 (1998)

Ferrarese, Laura, Bresolin, Fabio, Kennicutt, Robert C., Saha, Abhijit, Stetson, Peter B., ...

We report the detection of Cepheids and a new distance to the spiral galaxy NGC 2541, based on data obtained with the Wide Field and Planetary Camera 2 on board the Hubble Space Telescope (HST). A...

The Hubble Space Telescope Extragalactic Distance Scale Key Project. X. The Cepheid Distance to NGC 7331 (1998)

Han, Mingsheng, Hoessel, John, Freedman, Wendy L., Kennicutt, Robert C., Mould, Jeremy. R., ...

The distance to NGC 7331 has been derived from Cepheid variables observed with HST/WFPC2, as part of the Extragalactic Distance Scale Key Project. Multi-epoch exposures in F555W (V) and F814W (I),...

The Extragalactic Distance Scale Key Project VIII. The Discovery of Cepheids and a New Distance to NGC 3621 Using the Hubble Space Telescope (1997)

Rawson, Daya M., Macri, Lucas M., Mould, Jeremy R., Huchra, John P., Freedman, Wendy L., Kennicutt, Robert C., ...

We report on the discovery of Cepheids in the field spiral galaxy NGC 3621, based on observations made with the Wide Field and Planetary Camera 2 on board the Hubble Space Telescope (HST). NGC 3621...

HI 2334+26: An Extended HI Cloud near Abell 2634 (1994)

Giovanelli, Riccardo, Scodeggio, Marco, Solanes, Jose` M., Haynes, Martha P., Arce, Hector, Sakai, Shoko

We report the serendipitous discovery of a large HI cloud with an associated HI mass of $6(\pm1.5)\times 10^9 h^{-2}$ M$_\odot$ and a heliocentric velocity 8800 \kms, located near the periphery of...