As a prerequisite for interpreting new observations of the most distant radio galaxies, we make a... more As a prerequisite for interpreting new observations of the most distant radio galaxies, we make an optical study of the closest powerful radio source, Cygnus A. Using Keck imaging-and spectro-polarimetry in conjunction with HST, WFPC2 broad and narrow band imaging, we are able to identify speci c geometrical structures in the galaxy with optical continuum components distinguished by both colour and polarimetric properties. A 4 kpc diameter dusty ring of young stars forms the equator of a double ionization cone which is co-axial with the radio jets.
Deep learning has achieved great success in many applications. However, its deployment in practic... more Deep learning has achieved great success in many applications. However, its deployment in practice has been hurdled by two issues: the privacy of data that has to be aggregated centrally for model training and high communication overhead due to transmission of large amount of data usually geographically distributed. Addressing both issues is challenging and most existing works could not provide an efficient solution. In this paper, we develop FedPC, a Federated Deep Learning Framework for Privacy Preservation and Communication Efficiency. The framework allows a model to be learned on multiple private datasets while not revealing any information of training data, even with intermediate data. The framework also minimizes the amount of data exchanged to update the model. We formally prove the convergence of the learning model when training with FedPC and its privacy-preserving property. We perform extensive experiments to evaluate the performance of FedPC in terms of the approximation to the upper-bound performance (when training centrally) and communication overhead. The results show that FedPC maintains the performance approximation of the models within 8.5% of the centrally-trained models when data is distributed to 10 computing nodes. FedPC also reduces the communication overhead by up to 42.20% compared to existing works.
NGC 3147, NGC 4698, and 1ES 1927+654 are active galaxies that are classified as Seyfert 2s, based... more NGC 3147, NGC 4698, and 1ES 1927+654 are active galaxies that are classified as Seyfert 2s, based on the line ratios of strong narrow emission lines in their optical spectra. However, they exhibit rapid X-ray spectral variability and/or little indication of obscuration in X-ray spectral fitting, contrary to expectation from the active galactic nucleus (AGN) unification model. Using optical spectropolarimetry with LRIS and near-infrared spectroscopy with NIRSPEC at the W. M. Keck Observatory, we conducted a deep search for hidden polarized broad Hα and direct broad Paβ or Brγ emission lines in these objects. We found no evidence for any broad emission lines from the active nucleus of these galaxies, suggesting that they are unobscured, completely "naked" AGNs that intrinsically lack broad-line regions.
Universities for Research in Astronomy under cooperative agreement with the National Science Foun... more Universities for Research in Astronomy under cooperative agreement with the National Science Foundation. – 2 – We present Keck spectropolarimetry of two rare low-ionization broad absorption line (BAL) QSOs, FIRST J084044.5+363328 and FIRST J155633.8+351758, that also exhibit narrow absorption lines from metastable excited levels of Fe II (“Iron Lo-BALs”). These QSOs were discovered in optical follow-ups to a deep radio survey; FIRST J155633.8+351758 is radio-loud, the first BAL QSO so identified. FIRST J084044.5+363328 is highly polarized and exhibits many features found in other BAL QSOs. The continuum is ≈4 % polarized near 2000 ˚A rest-frame, falling to ≈2 % at longer wavelengths, at a position angle of ≈50 ◦. The emission lines are unpolarized. The polarization rises to ≈8 % in the low-ionization troughs of Mg II λ2800 and Al III λ1860. The polarization and its position angle vary in a complicated manner across the metastable Fe II
We present V and I continuum images and Hα+[N II] maps of nine early-type galaxies observed with ... more We present V and I continuum images and Hα+[N II] maps of nine early-type galaxies observed with the Wide Field Channel of the Advanced Camera for Surveys on the Hubble Space Telescope. Dust and ionized gas are detected in all galaxies. The optical nebulae are primarily concentrated on the nuclei and extend out to radii of a few hundred parsecs, in compact clumps, filaments, or disks. Two galaxies, NGC 6166 and NGC 6338, also possess diffuse, ionized filaments on kiloparsec scales. The ionized gas is entirely contained within the nuclear disks of ESO 208-G021, NGC 3078, and NGC 7720. In the radio-loud galaxy NGC 6166, emissionline filaments are detected along the radio lobes, possibly as a result of shock ionization. A wide range of ionized gas masses, Mg ≈ 7 × 10 2 − 3 × 10 6 M⊙, are calculated from the observed fluxes. Even in this small sample, the orientation of the ionized material correlates well with the major or minor axis of the galaxies, consistent with an external origin ...
A collaboration between the W. M. Keck Observatory (WMKO) in Hawaii and the NASA Exoplanet Scienc... more A collaboration between the W. M. Keck Observatory (WMKO) in Hawaii and the NASA Exoplanet Science Institute (NExScI) in California, the Keck Observatory Archive (KOA) was commissioned in 2004 to archive data from WMKO, which operates two classically scheduled 10 m ground-based telescopes. The data from Keck are not suitable for direct ingestion into the archive since the metadata contained in the original FITS headers lack the information necessary for proper archiving. The data pose a number of challenges for KOA: different instrument builders used different standards, and the nature of classical observing, where observers have complete control of the instruments and their observations, lead to heterogeneous data sets. For example, it is often difficult to determine if an observation is a science target, a sky frame, or a sky flat. It is also necessary to assign the data to the correct owners and observing programs, which can be a challenge for time-domain and target-of-opportunit...
The deployment of such deep learning in practice has been hurdled by two issues: the computationa... more The deployment of such deep learning in practice has been hurdled by two issues: the computational cost of model training and the privacy issue of training data such as medical or healthcare records. The large size of both learning models and datasets incurs a massive computational cost, requiring efficient approaches to speed up the training phase. While parallel and distributed learning can address the issue of computational overhead, preserving the privacy of training data and intermediate results (e.g., gradients) remains a hard problem. Enabling parallel training of deep learning models on distributed datasets while preserving data privacy is even more complex and challenging. In this paper, we develop and implement FEDF, a distributed deep learning framework for privacy-preserving and parallel training. The framework allows a model to be learned on multiple geographically-distributed training datasets (which may belong to different owners) while do not reveal any information o...
Bacterial biofilms are involved in most device-associated infections and remain a challenge for m... more Bacterial biofilms are involved in most device-associated infections and remain a challenge for modern medicine. One major approach to addressing this problem is to prevent the formation of biofilms using novel antimicrobial materials, device surface modification or local drug delivery; however, successful preventive measures are still extremely limited. The other approach is concerned with treating biofilms that have already formed on the devices; this approach is the focus of our manuscript. Treating biofilms associated with medical devices has unique challenges due to the biofilm’s extracellular polymer substance (EPS) and the biofilm bacteria’s resistance to most conventional antimicrobial agents. The treatment is further complicated by the fact that the treatment must be suitable for applying on devices surrounded by host tissue in many cases. Nanomaterials have been extensively investigated for preventing biofilm formation on medical devices, yet their applications in treating...
Observatory Operations: Strategies, Processes, and Systems VI, 2016
The Keck Observatory Archive (KOA) currently serves ~ 42 TB of data spanning over 20 years from a... more The Keck Observatory Archive (KOA) currently serves ~ 42 TB of data spanning over 20 years from all ten past and current facility instruments at Keck. Although most of the available data are in the raw form, for four instruments (HIRES, NIRC2, OSIRIS, LWS), quick-look, browse products generated by automated pipelines are also offered to facilitate assessment of the scientific content and quality of the data. KOA underwrote the update of the MAKEE package to support reduction of the CCD upgrade to HIRES, developed scripts for reduction of NIRC2 data and automated the existing OSIRIS and LWS data reduction packages. We describe in some detail the recently completed automated pipeline for NIRSPEC, which will be used to create browse products in KOA and made available for quicklook of the data by the observers at the telescope. We review the currently available data reduction tools for Keck data, and present our plans and anticipated priorities for the development of automated pipelines and release of reduced data products for the rest of the current and future instruments. We also anticipate that Keck's newest instrument, NIRES, which will be delivered with a fully automated pipeline, will be the first to have both raw and level-1 data ingested at commissioning.
Chloroquine remains the mainstay of treatment for Plasmodium vivax malaria despite increasing rep... more Chloroquine remains the mainstay of treatment for Plasmodium vivax malaria despite increasing reports of treatment failure. We did a systematic review and meta-analysis to investigate the effect of chloroquine dose and the addition of primaquine on the risk of recurrent vivax malaria across different settings. A systematic review done in MEDLINE, Web of Science, Embase, and Cochrane Database of Systematic Reviews identified P vivax clinical trials published between Jan 1, 2000, and March 22, 2017. Principal investigators were invited to share individual patient data, which were pooled using standardised methods. Cox regression analyses with random effects for study site were used to investigate the roles of chloroquine dose and primaquine use on rate of recurrence between day 7 and day 42 (primary outcome). The review protocol is registered in PROSPERO, number CRD42016053310. Of 134 identified chloroquine studies, 37 studies (from 17 countries) and 5240 patients were included. 2990 ...
Serum- and glucocorticoid-inducible kinases (SGKs) form a novel family of serine/threonine kinase... more Serum- and glucocorticoid-inducible kinases (SGKs) form a novel family of serine/threonine kinases that are activated in response to a variety of extracellular stimuli. SGKs are related to Akt (also called PKB), a serine/threonine kinase that plays a crucial role in promoting cell survival. Like Akt, SGKs are activated by the phosphoinositide-3 kinase (PI3K) and translocate to the nucleus upon growth factor stimulation. However the physiological substrates and cellular functions of SGKs remained to be identified. We hypothesized that SGKs regulate cellular functions in concert with Akt by phosphorylating common targets within the nucleus. The best-characterized nuclear substrates of Akt are transcription factors of the Forkhead family. Akt phosphorylates Forkhead transcription factors such as FKHRL1, leading to FKHRL1's exit from the nucleus and the consequent shutoff of FKHRL1 target genes. We show here that SGK1, like Akt, promotes cell survival and that it does so in part by ...
The Advanced Camera for Surveys (ACS) on-board the Hubble Space Telescope (HST) is equipped with ... more The Advanced Camera for Surveys (ACS) on-board the Hubble Space Telescope (HST) is equipped with a set of ramp filters which provide imaging capability at 2% and 9% bandwidth in the range 3700-10700 Å. Each ramp filter consist of three segments where the middle segment can be used with both the Wide Field Channel (WFC) and High Resolution Channel (HRC), while the inner and outer segments can be used only with WFC. The monochromatic field of view is approximately 40'' by 80''. We will present observations of the planetary nebula (PN) NGC6543 (the Cat's Eye) taken with the ACS ramp filetrs in several key emission lines - [O II] 3727, [O III] 5007, H-alpha+[N II], and [S II] 6725. These four emission lines fall onto three separate middle ramp segments - FR388N, FR505N, and FR656N - and will allow inter-comparison between the ACS ramp filters and fixed bandpass narrow-band filters F502N and F658N for both the WFC and HRC detectors. These observations were taken as pa...
We present the first observations of merging galaxies using the Wide Field Channel (WFC) of the A... more We present the first observations of merging galaxies using the Wide Field Channel (WFC) of the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope (HST). The deep images, made through the F475W, F606W and F814W filters, were obtained as part of the early release observations (EROs) to demonstrate the new capabilities of ACS. We describe the search and
Background: Hepatitis B and liver cancer are extremely serious diseases that affect Asian America... more Background: Hepatitis B and liver cancer are extremely serious diseases that affect Asian Americans disproportionately. Ethnic group specific non-traditional educational material is needed. Objective: To develop culturally tailored photonovels to prevent hepatitis B and liver cancer. Methods: Findings from eight focus groups with Chinese, Korean, and Vietnamese Americans (58 participants) conducted in 2009 were used to create storylines tailored for each group. Each community's input was reflected in storyline, fact boxes, readability, cover, and design. Community-specific settings were used, and actors/actresses were recruited from the community. Results: Focus group findings indicated that participants' level of knowledge for hepatitis B and screening/vaccination was generally low, but some key barriers to hepatitis B screening/vaccination differed significantly by group. Stigma was the primary barrier for Chinese, heavy reliance on alternative medicine, supplements, and f...
We present early results from recent imaging of the GG Tauri binary star system and circumbinary ... more We present early results from recent imaging of the GG Tauri binary star system and circumbinary disk at V and I passbands using the HST/ACS High Resolution Camera. Deep exposures combined with PSF subtraction provide images of the disk with higher contrast and resolution than were previously possible from the ground or HST. The disk, which appears as a ring
As a service to the astronomical community, Fred Chaffee and Team Keck joined with collaborators ... more As a service to the astronomical community, Fred Chaffee and Team Keck joined with collaborators at UH-IfA, UCSC, and UC Berkeley to obtain DEIMOS spectra for nearly 2000 of the roughly 2700 objects in the GOODS-North field. The GOODS (Great Observatories Origins Deep Survey) program is a 320-square arcminute imaging survey in two fields (GOODS-North and GOODS-South). These fields are
The Keck Observatory Archive (KOA) began operations on August 19, 2004. The KOA is now ingesting ... more The Keck Observatory Archive (KOA) began operations on August 19, 2004. The KOA is now ingesting observations made with the upgraded three-CCD mosaic on the High Resolution Echelle Spectrometer (HIRES), archiving all level-0 (raw) data from HIRES. After each night of HIRES observations, the archive software at W. M. Keck Observatory finds all data taken in the previous 24 hour
We report the discovery of WN J0717+4611, a highly polarized red quasar at z = 1.462, selected fr... more We report the discovery of WN J0717+4611, a highly polarized red quasar at z = 1.462, selected from a sample of faint (S 1.4GHz > 10 mJy) ultra steep spectrum (α 327 1400 < −1.3; S ∝ ν α) radio sources. VLA observations at 4.85 GHz show that the radio source is dominated by a 21 mJy core. Using the Keck telescopes, we obtained spectra with a combined wavelength range covering 4000Å to 1.6 µm, and spectropolarimetric observations between 4000Å and 9000Å. We identify WN J0717+4611 as a quasar based on broad emission of Mg II λ2799 (FWHM ≃ 11,000 km s −1), a stellar R S-band Lick image and the high luminosity of the object (M B = −24.2). The optical linear polarization is wavelength-independent at 15% in both the continuum and the emission lines, with the polarization angle orthogonal to the radio jet axis. We argue that the polarization mechanism is scattering of quasar light by surrounding small dust grains or electrons. WN J0717+4611 appears highly reddened for a core-dominated quasar.
A five square arcminute region around the luminous radio-loud quasar SDSS J0836+0054 (z = 5.8) ho... more A five square arcminute region around the luminous radio-loud quasar SDSS J0836+0054 (z = 5.8) hosts a wealth of associated galaxies, characterized by very red (1.3 < i 775 − z 850 < 2.0) color. The surface density of these z ∼ 5.8 candidates is approximately six times higher than the number expected from deep ACS fields. This is one of the highest galaxy overdensities at high redshifts, which may develop into a group or cluster. We also find evidence for a sub
As a prerequisite for interpreting new observations of the most distant radio galaxies, we make a... more As a prerequisite for interpreting new observations of the most distant radio galaxies, we make an optical study of the closest powerful radio source, Cygnus A. Using Keck imaging-and spectro-polarimetry in conjunction with HST, WFPC2 broad and narrow band imaging, we are able to identify speci c geometrical structures in the galaxy with optical continuum components distinguished by both colour and polarimetric properties. A 4 kpc diameter dusty ring of young stars forms the equator of a double ionization cone which is co-axial with the radio jets.
Deep learning has achieved great success in many applications. However, its deployment in practic... more Deep learning has achieved great success in many applications. However, its deployment in practice has been hurdled by two issues: the privacy of data that has to be aggregated centrally for model training and high communication overhead due to transmission of large amount of data usually geographically distributed. Addressing both issues is challenging and most existing works could not provide an efficient solution. In this paper, we develop FedPC, a Federated Deep Learning Framework for Privacy Preservation and Communication Efficiency. The framework allows a model to be learned on multiple private datasets while not revealing any information of training data, even with intermediate data. The framework also minimizes the amount of data exchanged to update the model. We formally prove the convergence of the learning model when training with FedPC and its privacy-preserving property. We perform extensive experiments to evaluate the performance of FedPC in terms of the approximation to the upper-bound performance (when training centrally) and communication overhead. The results show that FedPC maintains the performance approximation of the models within 8.5% of the centrally-trained models when data is distributed to 10 computing nodes. FedPC also reduces the communication overhead by up to 42.20% compared to existing works.
NGC 3147, NGC 4698, and 1ES 1927+654 are active galaxies that are classified as Seyfert 2s, based... more NGC 3147, NGC 4698, and 1ES 1927+654 are active galaxies that are classified as Seyfert 2s, based on the line ratios of strong narrow emission lines in their optical spectra. However, they exhibit rapid X-ray spectral variability and/or little indication of obscuration in X-ray spectral fitting, contrary to expectation from the active galactic nucleus (AGN) unification model. Using optical spectropolarimetry with LRIS and near-infrared spectroscopy with NIRSPEC at the W. M. Keck Observatory, we conducted a deep search for hidden polarized broad Hα and direct broad Paβ or Brγ emission lines in these objects. We found no evidence for any broad emission lines from the active nucleus of these galaxies, suggesting that they are unobscured, completely "naked" AGNs that intrinsically lack broad-line regions.
Universities for Research in Astronomy under cooperative agreement with the National Science Foun... more Universities for Research in Astronomy under cooperative agreement with the National Science Foundation. – 2 – We present Keck spectropolarimetry of two rare low-ionization broad absorption line (BAL) QSOs, FIRST J084044.5+363328 and FIRST J155633.8+351758, that also exhibit narrow absorption lines from metastable excited levels of Fe II (“Iron Lo-BALs”). These QSOs were discovered in optical follow-ups to a deep radio survey; FIRST J155633.8+351758 is radio-loud, the first BAL QSO so identified. FIRST J084044.5+363328 is highly polarized and exhibits many features found in other BAL QSOs. The continuum is ≈4 % polarized near 2000 ˚A rest-frame, falling to ≈2 % at longer wavelengths, at a position angle of ≈50 ◦. The emission lines are unpolarized. The polarization rises to ≈8 % in the low-ionization troughs of Mg II λ2800 and Al III λ1860. The polarization and its position angle vary in a complicated manner across the metastable Fe II
We present V and I continuum images and Hα+[N II] maps of nine early-type galaxies observed with ... more We present V and I continuum images and Hα+[N II] maps of nine early-type galaxies observed with the Wide Field Channel of the Advanced Camera for Surveys on the Hubble Space Telescope. Dust and ionized gas are detected in all galaxies. The optical nebulae are primarily concentrated on the nuclei and extend out to radii of a few hundred parsecs, in compact clumps, filaments, or disks. Two galaxies, NGC 6166 and NGC 6338, also possess diffuse, ionized filaments on kiloparsec scales. The ionized gas is entirely contained within the nuclear disks of ESO 208-G021, NGC 3078, and NGC 7720. In the radio-loud galaxy NGC 6166, emissionline filaments are detected along the radio lobes, possibly as a result of shock ionization. A wide range of ionized gas masses, Mg ≈ 7 × 10 2 − 3 × 10 6 M⊙, are calculated from the observed fluxes. Even in this small sample, the orientation of the ionized material correlates well with the major or minor axis of the galaxies, consistent with an external origin ...
A collaboration between the W. M. Keck Observatory (WMKO) in Hawaii and the NASA Exoplanet Scienc... more A collaboration between the W. M. Keck Observatory (WMKO) in Hawaii and the NASA Exoplanet Science Institute (NExScI) in California, the Keck Observatory Archive (KOA) was commissioned in 2004 to archive data from WMKO, which operates two classically scheduled 10 m ground-based telescopes. The data from Keck are not suitable for direct ingestion into the archive since the metadata contained in the original FITS headers lack the information necessary for proper archiving. The data pose a number of challenges for KOA: different instrument builders used different standards, and the nature of classical observing, where observers have complete control of the instruments and their observations, lead to heterogeneous data sets. For example, it is often difficult to determine if an observation is a science target, a sky frame, or a sky flat. It is also necessary to assign the data to the correct owners and observing programs, which can be a challenge for time-domain and target-of-opportunit...
The deployment of such deep learning in practice has been hurdled by two issues: the computationa... more The deployment of such deep learning in practice has been hurdled by two issues: the computational cost of model training and the privacy issue of training data such as medical or healthcare records. The large size of both learning models and datasets incurs a massive computational cost, requiring efficient approaches to speed up the training phase. While parallel and distributed learning can address the issue of computational overhead, preserving the privacy of training data and intermediate results (e.g., gradients) remains a hard problem. Enabling parallel training of deep learning models on distributed datasets while preserving data privacy is even more complex and challenging. In this paper, we develop and implement FEDF, a distributed deep learning framework for privacy-preserving and parallel training. The framework allows a model to be learned on multiple geographically-distributed training datasets (which may belong to different owners) while do not reveal any information o...
Bacterial biofilms are involved in most device-associated infections and remain a challenge for m... more Bacterial biofilms are involved in most device-associated infections and remain a challenge for modern medicine. One major approach to addressing this problem is to prevent the formation of biofilms using novel antimicrobial materials, device surface modification or local drug delivery; however, successful preventive measures are still extremely limited. The other approach is concerned with treating biofilms that have already formed on the devices; this approach is the focus of our manuscript. Treating biofilms associated with medical devices has unique challenges due to the biofilm’s extracellular polymer substance (EPS) and the biofilm bacteria’s resistance to most conventional antimicrobial agents. The treatment is further complicated by the fact that the treatment must be suitable for applying on devices surrounded by host tissue in many cases. Nanomaterials have been extensively investigated for preventing biofilm formation on medical devices, yet their applications in treating...
Observatory Operations: Strategies, Processes, and Systems VI, 2016
The Keck Observatory Archive (KOA) currently serves ~ 42 TB of data spanning over 20 years from a... more The Keck Observatory Archive (KOA) currently serves ~ 42 TB of data spanning over 20 years from all ten past and current facility instruments at Keck. Although most of the available data are in the raw form, for four instruments (HIRES, NIRC2, OSIRIS, LWS), quick-look, browse products generated by automated pipelines are also offered to facilitate assessment of the scientific content and quality of the data. KOA underwrote the update of the MAKEE package to support reduction of the CCD upgrade to HIRES, developed scripts for reduction of NIRC2 data and automated the existing OSIRIS and LWS data reduction packages. We describe in some detail the recently completed automated pipeline for NIRSPEC, which will be used to create browse products in KOA and made available for quicklook of the data by the observers at the telescope. We review the currently available data reduction tools for Keck data, and present our plans and anticipated priorities for the development of automated pipelines and release of reduced data products for the rest of the current and future instruments. We also anticipate that Keck's newest instrument, NIRES, which will be delivered with a fully automated pipeline, will be the first to have both raw and level-1 data ingested at commissioning.
Chloroquine remains the mainstay of treatment for Plasmodium vivax malaria despite increasing rep... more Chloroquine remains the mainstay of treatment for Plasmodium vivax malaria despite increasing reports of treatment failure. We did a systematic review and meta-analysis to investigate the effect of chloroquine dose and the addition of primaquine on the risk of recurrent vivax malaria across different settings. A systematic review done in MEDLINE, Web of Science, Embase, and Cochrane Database of Systematic Reviews identified P vivax clinical trials published between Jan 1, 2000, and March 22, 2017. Principal investigators were invited to share individual patient data, which were pooled using standardised methods. Cox regression analyses with random effects for study site were used to investigate the roles of chloroquine dose and primaquine use on rate of recurrence between day 7 and day 42 (primary outcome). The review protocol is registered in PROSPERO, number CRD42016053310. Of 134 identified chloroquine studies, 37 studies (from 17 countries) and 5240 patients were included. 2990 ...
Serum- and glucocorticoid-inducible kinases (SGKs) form a novel family of serine/threonine kinase... more Serum- and glucocorticoid-inducible kinases (SGKs) form a novel family of serine/threonine kinases that are activated in response to a variety of extracellular stimuli. SGKs are related to Akt (also called PKB), a serine/threonine kinase that plays a crucial role in promoting cell survival. Like Akt, SGKs are activated by the phosphoinositide-3 kinase (PI3K) and translocate to the nucleus upon growth factor stimulation. However the physiological substrates and cellular functions of SGKs remained to be identified. We hypothesized that SGKs regulate cellular functions in concert with Akt by phosphorylating common targets within the nucleus. The best-characterized nuclear substrates of Akt are transcription factors of the Forkhead family. Akt phosphorylates Forkhead transcription factors such as FKHRL1, leading to FKHRL1's exit from the nucleus and the consequent shutoff of FKHRL1 target genes. We show here that SGK1, like Akt, promotes cell survival and that it does so in part by ...
The Advanced Camera for Surveys (ACS) on-board the Hubble Space Telescope (HST) is equipped with ... more The Advanced Camera for Surveys (ACS) on-board the Hubble Space Telescope (HST) is equipped with a set of ramp filters which provide imaging capability at 2% and 9% bandwidth in the range 3700-10700 Å. Each ramp filter consist of three segments where the middle segment can be used with both the Wide Field Channel (WFC) and High Resolution Channel (HRC), while the inner and outer segments can be used only with WFC. The monochromatic field of view is approximately 40'' by 80''. We will present observations of the planetary nebula (PN) NGC6543 (the Cat's Eye) taken with the ACS ramp filetrs in several key emission lines - [O II] 3727, [O III] 5007, H-alpha+[N II], and [S II] 6725. These four emission lines fall onto three separate middle ramp segments - FR388N, FR505N, and FR656N - and will allow inter-comparison between the ACS ramp filters and fixed bandpass narrow-band filters F502N and F658N for both the WFC and HRC detectors. These observations were taken as pa...
We present the first observations of merging galaxies using the Wide Field Channel (WFC) of the A... more We present the first observations of merging galaxies using the Wide Field Channel (WFC) of the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope (HST). The deep images, made through the F475W, F606W and F814W filters, were obtained as part of the early release observations (EROs) to demonstrate the new capabilities of ACS. We describe the search and
Background: Hepatitis B and liver cancer are extremely serious diseases that affect Asian America... more Background: Hepatitis B and liver cancer are extremely serious diseases that affect Asian Americans disproportionately. Ethnic group specific non-traditional educational material is needed. Objective: To develop culturally tailored photonovels to prevent hepatitis B and liver cancer. Methods: Findings from eight focus groups with Chinese, Korean, and Vietnamese Americans (58 participants) conducted in 2009 were used to create storylines tailored for each group. Each community's input was reflected in storyline, fact boxes, readability, cover, and design. Community-specific settings were used, and actors/actresses were recruited from the community. Results: Focus group findings indicated that participants' level of knowledge for hepatitis B and screening/vaccination was generally low, but some key barriers to hepatitis B screening/vaccination differed significantly by group. Stigma was the primary barrier for Chinese, heavy reliance on alternative medicine, supplements, and f...
We present early results from recent imaging of the GG Tauri binary star system and circumbinary ... more We present early results from recent imaging of the GG Tauri binary star system and circumbinary disk at V and I passbands using the HST/ACS High Resolution Camera. Deep exposures combined with PSF subtraction provide images of the disk with higher contrast and resolution than were previously possible from the ground or HST. The disk, which appears as a ring
As a service to the astronomical community, Fred Chaffee and Team Keck joined with collaborators ... more As a service to the astronomical community, Fred Chaffee and Team Keck joined with collaborators at UH-IfA, UCSC, and UC Berkeley to obtain DEIMOS spectra for nearly 2000 of the roughly 2700 objects in the GOODS-North field. The GOODS (Great Observatories Origins Deep Survey) program is a 320-square arcminute imaging survey in two fields (GOODS-North and GOODS-South). These fields are
The Keck Observatory Archive (KOA) began operations on August 19, 2004. The KOA is now ingesting ... more The Keck Observatory Archive (KOA) began operations on August 19, 2004. The KOA is now ingesting observations made with the upgraded three-CCD mosaic on the High Resolution Echelle Spectrometer (HIRES), archiving all level-0 (raw) data from HIRES. After each night of HIRES observations, the archive software at W. M. Keck Observatory finds all data taken in the previous 24 hour
We report the discovery of WN J0717+4611, a highly polarized red quasar at z = 1.462, selected fr... more We report the discovery of WN J0717+4611, a highly polarized red quasar at z = 1.462, selected from a sample of faint (S 1.4GHz > 10 mJy) ultra steep spectrum (α 327 1400 < −1.3; S ∝ ν α) radio sources. VLA observations at 4.85 GHz show that the radio source is dominated by a 21 mJy core. Using the Keck telescopes, we obtained spectra with a combined wavelength range covering 4000Å to 1.6 µm, and spectropolarimetric observations between 4000Å and 9000Å. We identify WN J0717+4611 as a quasar based on broad emission of Mg II λ2799 (FWHM ≃ 11,000 km s −1), a stellar R S-band Lick image and the high luminosity of the object (M B = −24.2). The optical linear polarization is wavelength-independent at 15% in both the continuum and the emission lines, with the polarization angle orthogonal to the radio jet axis. We argue that the polarization mechanism is scattering of quasar light by surrounding small dust grains or electrons. WN J0717+4611 appears highly reddened for a core-dominated quasar.
A five square arcminute region around the luminous radio-loud quasar SDSS J0836+0054 (z = 5.8) ho... more A five square arcminute region around the luminous radio-loud quasar SDSS J0836+0054 (z = 5.8) hosts a wealth of associated galaxies, characterized by very red (1.3 < i 775 − z 850 < 2.0) color. The surface density of these z ∼ 5.8 candidates is approximately six times higher than the number expected from deep ACS fields. This is one of the highest galaxy overdensities at high redshifts, which may develop into a group or cluster. We also find evidence for a sub
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