Recursos de colección

Caltech Authors (162.548 recursos)

Repository of works by Caltech published authors.

Group = IPTF

Mostrando recursos 61 - 80 de 285

  1. iPTF Search for an Optical Counterpart to Gravitational-wave Transient GW150914

    Kasliwal, M. M.; Cao, Y.; Barlow, T.; Bellm, E.; Cook, D.; Duggan, G. E.; Kulkarni, S. R.; Lunnan, R.; Laher, R.; Masci, F.; Miller, A. A.; Prince, T. A.; Surace, J.
    The intermediate Palomar Transient Factory (iPTF) autonomously responded to and promptly tiled the error region of the first gravitational-wave event GW150914 to search for an optical counterpart. Only a small fraction of the total localized region was immediately visible in the northern night sky, due both to Sun-angle and elevation constraints. Here, we report on the transient candidates identified and rapid follow-up undertaken to determine the nature of each candidate. Even in the small area imaged of 126 deg^2, after extensive filtering, eight candidates were deemed worthy of additional follow-up. Within two hours, all eight were spectroscopically classified by the...

  2. iPTF Search for an Optical Counterpart to Gravitational-wave Transient GW150914

    Kasliwal, M. M.; Cao, Y.; Barlow, T.; Bellm, E.; Cook, D.; Duggan, G. E.; Kulkarni, S. R.; Lunnan, R.; Laher, R.; Masci, F.; Miller, A. A.; Prince, T. A.; Surace, J.
    The intermediate Palomar Transient Factory (iPTF) autonomously responded to and promptly tiled the error region of the first gravitational-wave event GW150914 to search for an optical counterpart. Only a small fraction of the total localized region was immediately visible in the northern night sky, due both to Sun-angle and elevation constraints. Here, we report on the transient candidates identified and rapid follow-up undertaken to determine the nature of each candidate. Even in the small area imaged of 126 deg^2, after extensive filtering, eight candidates were deemed worthy of additional follow-up. Within two hours, all eight were spectroscopically classified by the...

  3. iPTF Search for an Optical Counterpart to Gravitational-wave Transient GW150914

    Kasliwal, M. M.; Cao, Y.; Barlow, T.; Bellm, E.; Cook, D.; Duggan, G. E.; Kulkarni, S. R.; Lunnan, R.; Laher, R.; Masci, F.; Miller, A. A.; Prince, T. A.; Surace, J.
    The intermediate Palomar Transient Factory (iPTF) autonomously responded to and promptly tiled the error region of the first gravitational-wave event GW150914 to search for an optical counterpart. Only a small fraction of the total localized region was immediately visible in the northern night sky, due both to Sun-angle and elevation constraints. Here, we report on the transient candidates identified and rapid follow-up undertaken to determine the nature of each candidate. Even in the small area imaged of 126 deg^2, after extensive filtering, eight candidates were deemed worthy of additional follow-up. Within two hours, all eight were spectroscopically classified by the...

  4. iPTF Search for an Optical Counterpart to Gravitational-wave Transient GW150914

    Kasliwal, M. M.; Cao, Y.; Barlow, T.; Bellm, E.; Cook, D.; Duggan, G. E.; Kulkarni, S. R.; Lunnan, R.; Laher, R.; Masci, F.; Miller, A. A.; Prince, T. A.; Surace, J.
    The intermediate Palomar Transient Factory (iPTF) autonomously responded to and promptly tiled the error region of the first gravitational-wave event GW150914 to search for an optical counterpart. Only a small fraction of the total localized region was immediately visible in the northern night sky, due both to Sun-angle and elevation constraints. Here, we report on the transient candidates identified and rapid follow-up undertaken to determine the nature of each candidate. Even in the small area imaged of 126 deg^2, after extensive filtering, eight candidates were deemed worthy of additional follow-up. Within two hours, all eight were spectroscopically classified by the...

  5. Be Stars in the Open Cluster NGC 6830

    Yu, Po-Chieh; Lin, Chien-Cheng; Lin, Hsing-Wen; Lee, Chien-De; Konidaris, Nick; Ngeow, Chow-Choong; Ip, Wing-Huen; Chen, Wen-Ping; Chen, Hui-Chen; Malkan, Matthew A.; Chang, Chan-Kao; Laher, Russ; Huang, Li-Ching; Cheng, Yu-Chi; Edelson, Rick; Ritter, Andreas; Quimby, Robert; Ben-Ami, Sagi; Ofek, Eran O.; Surace, Jason; Kulkarni, Shrinivas R.
    We report the discovery of two new Be stars, and re-identify one known Be star in the open cluster NGC 6830. Eleven Hα emitters were discovered using the Hα imaging photometry of the Palomar Transient Factory Survey. Stellar membership of the candidates was verified with photometric and kinematic information using 2MASS data and proper motions. The spectroscopic confirmation was carried out by using the Shane 3 m telescope at the Lick observatory. Based on their spectral types, three Hα emitters were confirmed as Be stars with Hα equivalent widths greater than −10 Å. Two objects were also observed by the...

  6. Be Stars in the Open Cluster NGC 6830

    Yu, Po-Chieh; Lin, Chien-Cheng; Lin, Hsing-Wen; Lee, Chien-De; Konidaris, Nick; Ngeow, Chow-Choong; Ip, Wing-Huen; Chen, Wen-Ping; Chen, Hui-Chen; Malkan, Matthew A.; Chang, Chan-Kao; Laher, Russ; Huang, Li-Ching; Cheng, Yu-Chi; Edelson, Rick; Ritter, Andreas; Quimby, Robert; Ben-Ami, Sagi; Ofek, Eran O.; Surace, Jason; Kulkarni, Shrinivas R.
    We report the discovery of two new Be stars, and re-identify one known Be star in the open cluster NGC 6830. Eleven Hα emitters were discovered using the Hα imaging photometry of the Palomar Transient Factory Survey. Stellar membership of the candidates was verified with photometric and kinematic information using 2MASS data and proper motions. The spectroscopic confirmation was carried out by using the Shane 3 m telescope at the Lick observatory. Based on their spectral types, three Hα emitters were confirmed as Be stars with Hα equivalent widths greater than −10 Å. Two objects were also observed by the...

  7. Be Stars in the Open Cluster NGC 6830

    Yu, Po-Chieh; Lin, Chien-Cheng; Lin, Hsing-Wen; Lee, Chien-De; Konidaris, Nick; Ngeow, Chow-Choong; Ip, Wing-Huen; Chen, Wen-Ping; Chen, Hui-Chen; Malkan, Matthew A.; Chang, Chan-Kao; Laher, Russ; Huang, Li-Ching; Cheng, Yu-Chi; Edelson, Rick; Ritter, Andreas; Quimby, Robert; Ben-Ami, Sagi; Ofek, Eran O.; Surace, Jason; Kulkarni, Shrinivas R.
    We report the discovery of two new Be stars, and re-identify one known Be star in the open cluster NGC 6830. Eleven Hα emitters were discovered using the Hα imaging photometry of the Palomar Transient Factory Survey. Stellar membership of the candidates was verified with photometric and kinematic information using 2MASS data and proper motions. The spectroscopic confirmation was carried out by using the Shane 3 m telescope at the Lick observatory. Based on their spectral types, three Hα emitters were confirmed as Be stars with Hα equivalent widths greater than −10 Å. Two objects were also observed by the...

  8. CHIMERA: a wide-field, multi-colour, high-speed photometer at the prime focus of the Hale telescope

    Harding, L. K.; Hallinan, G.; Milburn, J.; Gardner, P.; Konidaris, N.; Singh, N.; Shao, M.; Sandhu, J.; Kyne, G.; Schlichting, H. E.
    The Caltech HIgh-speed Multi-colour camERA (CHIMERA) is a new instrument that has been developed for use at the prime focus of the Hale 200-inch telescope. Simultaneous optical imaging in two bands is enabled by a dichroic beam splitter centred at 567 nm, with Sloan u′ and g′ bands available on the blue arm and Sloan r′, i′ and z_s bands available on the red arm. Additional narrow-band filters will also become available as required. An electron multiplying CCD (EMCCD) detector is employed for both optical channels, each capable of simultaneously delivering sub-electron effective read noise under multiplication gain and frame...

  9. Metallicity from Type II supernovae from the (i)PTF

    Taddia, F.; Moquist, P.; Sollerman, J.; Rubin, A.; Leloudas, G.; Gal-Yam, A.; Arcavi, I.; Cao, Y.; Filippenko, A. V.; Graham, M. L.; Mazzali, P. A.; Nugent, P. E.; Pan, Y.-C.; Silverman, J. M.; Xu, D.; Yaron, O.
    Type IIP supernovae (SNe IIP) have recently been proposed as metallicity (Z) probes. The spectral models of Dessart et al. (2014, MNRAS, 440, 1856) showed that the pseudo-equivalent width of Fe II λ5018 (pEW_(5018)) during the plateau phase depends on the primordial Z, but there was a paucity of SNe IIP exhibiting pEW_(5018) that were compatible with Z < 0.4 Z⊙. This lack might be due to some physical property of the SN II population or to the fact that those SNe have been discovered in luminous, metal-rich targeted galaxies. Here we use SN II observations from the untargeted (intermediate) Palomar...

  10. Metallicity from Type II supernovae from the (i)PTF

    Taddia, F.; Moquist, P.; Sollerman, J.; Rubin, A.; Leloudas, G.; Gal-Yam, A.; Arcavi, I.; Cao, Y.; Filippenko, A. V.; Graham, M. L.; Mazzali, P. A.; Nugent, P. E.; Pan, Y.-C.; Silverman, J. M.; Xu, D.; Yaron, O.
    Type IIP supernovae (SNe IIP) have recently been proposed as metallicity (Z) probes. The spectral models of Dessart et al. (2014, MNRAS, 440, 1856) showed that the pseudo-equivalent width of Fe II λ5018 (pEW_(5018)) during the plateau phase depends on the primordial Z, but there was a paucity of SNe IIP exhibiting pEW_(5018) that were compatible with Z < 0.4 Z⊙. This lack might be due to some physical property of the SN II population or to the fact that those SNe have been discovered in luminous, metal-rich targeted galaxies. Here we use SN II observations from the untargeted (intermediate) Palomar...

  11. Metallicity from Type II supernovae from the (i)PTF

    Taddia, F.; Moquist, P.; Sollerman, J.; Rubin, A.; Leloudas, G.; Gal-Yam, A.; Arcavi, I.; Cao, Y.; Filippenko, A. V.; Graham, M. L.; Mazzali, P. A.; Nugent, P. E.; Pan, Y.-C.; Silverman, J. M.; Xu, D.; Yaron, O.
    Type IIP supernovae (SNe IIP) have recently been proposed as metallicity (Z) probes. The spectral models of Dessart et al. (2014, MNRAS, 440, 1856) showed that the pseudo-equivalent width of Fe II λ5018 (pEW_(5018)) during the plateau phase depends on the primordial Z, but there was a paucity of SNe IIP exhibiting pEW_(5018) that were compatible with Z < 0.4 Z⊙. This lack might be due to some physical property of the SN II population or to the fact that those SNe have been discovered in luminous, metal-rich targeted galaxies. Here we use SN II observations from the untargeted (intermediate) Palomar...

  12. The Outer Galactic Halo As Probed By RR Lyr Stars From the Palomar Transient Facility + Keck

    Cohen, Judith; Sesar, Branimir; Banholzer, Sophianna
    We present initial results from our study of the outer halo of the Milky Way using a large sample of RR Lyr(ab) variables datamined from the archives of the Palomar Transient Facility. Of the 464 RR Lyr in our sample with distances exceeding 50 kpc, 62 have been observed spectroscopically at the Keck Observatory. v _r and σ(v_r) are given as a function of distance between 50 and 110 kpc, and a very preliminary rather low total mass for the Milky Way out to 110 kpc of ~7 ± 1.5 × 10^(11) M⊙ is derived from our data.

  13. The Outer Galactic Halo As Probed By RR Lyr Stars From the Palomar Transient Facility + Keck

    Cohen, Judith; Sesar, Branimir; Banholzer, Sophianna
    We present initial results from our study of the outer halo of the Milky Way using a large sample of RR Lyr(ab) variables datamined from the archives of the Palomar Transient Facility. Of the 464 RR Lyr in our sample with distances exceeding 50 kpc, 62 have been observed spectroscopically at the Keck Observatory. v _r and σ(v_r) are given as a function of distance between 50 and 110 kpc, and a very preliminary rather low total mass for the Milky Way out to 110 kpc of ~7 ± 1.5 × 10^(11) M⊙ is derived from our data.

  14. Properties and Evolution of the Redback Millisecond Pulsar Binary PSR J2129-0429

    Bellm, Eric C.; Kaplan, David L.; Breton, Rene P.; Phinney, E. Sterl; Bhalerao, Varun B.; Camilo, Fernando; Dahal, Sumit; Djorgovski, S. G.; Drake, Andrew J.; Hessels, J. W. T.; Laher, Russ R.; Levitan, David B.; Lewis, Fraser; Mahabal, Ashish A.; Ofek, Eran O.; Prince, Thomas A.; Ransom, Scott M.; Roberts, Mallory S. E.; Russell, David M.; Sesar, Branimir; Surace, Jason A.; Tang, Sumin
    PSR J2129−0429 is a "redback" eclipsing millisecond pulsar binary with an unusually long 15.2 hr orbit. It was discovered by the Green Bank Telescope in a targeted search of unidentified Fermi gamma-ray sources. The pulsar companion is optically bright (mean m_R = 16.6 mag), allowing us to construct the longest baseline photometric data set available for such a system. We present 10 years of archival and new photometry of the companion from the Lincoln Near-Earth Asteroid Research Survey, the Catalina Real-time Transient Survey, the Palomar Transient Factory, the Palomar 60 inch, and the Las Cumbres Observatory Global Telescope. Radial velocity...

  15. Properties and Evolution of the Redback Millisecond Pulsar Binary PSR J2129-0429

    Bellm, Eric C.; Kaplan, David L.; Breton, Rene P.; Phinney, E. Sterl; Bhalerao, Varun B.; Camilo, Fernando; Dahal, Sumit; Djorgovski, S. G.; Drake, Andrew J.; Hessels, J. W. T.; Laher, Russ R.; Levitan, David B.; Lewis, Fraser; Mahabal, Ashish A.; Ofek, Eran O.; Prince, Thomas A.; Ransom, Scott M.; Roberts, Mallory S. E.; Russell, David M.; Sesar, Branimir; Surace, Jason A.; Tang, Sumin
    PSR J2129−0429 is a "redback" eclipsing millisecond pulsar binary with an unusually long 15.2 hr orbit. It was discovered by the Green Bank Telescope in a targeted search of unidentified Fermi gamma-ray sources. The pulsar companion is optically bright (mean m_R = 16.6 mag), allowing us to construct the longest baseline photometric data set available for such a system. We present 10 years of archival and new photometry of the companion from the Lincoln Near-Earth Asteroid Research Survey, the Catalina Real-time Transient Survey, the Palomar Transient Factory, the Palomar 60 inch, and the Las Cumbres Observatory Global Telescope. Radial velocity...

  16. Properties and Evolution of the Redback Millisecond Pulsar Binary PSR J2129-0429

    Bellm, Eric C.; Kaplan, David L.; Breton, Rene P.; Phinney, E. Sterl; Bhalerao, Varun B.; Camilo, Fernando; Dahal, Sumit; Djorgovski, S. G.; Drake, Andrew J.; Hessels, J. W. T.; Laher, Russ R.; Levitan, David B.; Lewis, Fraser; Mahabal, Ashish A.; Ofek, Eran O.; Prince, Thomas A.; Ransom, Scott M.; Roberts, Mallory S. E.; Russell, David M.; Sesar, Branimir; Surace, Jason A.; Tang, Sumin
    PSR J2129−0429 is a "redback" eclipsing millisecond pulsar binary with an unusually long 15.2 hr orbit. It was discovered by the Green Bank Telescope in a targeted search of unidentified Fermi gamma-ray sources. The pulsar companion is optically bright (mean m_R = 16.6 mag), allowing us to construct the longest baseline photometric data set available for such a system. We present 10 years of archival and new photometry of the companion from the Lincoln Near-Earth Asteroid Research Survey, the Catalina Real-time Transient Survey, the Palomar Transient Factory, the Palomar 60 inch, and the Las Cumbres Observatory Global Telescope. Radial velocity...

  17. Properties and Evolution of the Redback Millisecond Pulsar Binary PSR J2129-0429

    Bellm, Eric C.; Kaplan, David L.; Breton, Rene P.; Phinney, E. Sterl; Bhalerao, Varun B.; Camilo, Fernando; Dahal, Sumit; Djorgovski, S. G.; Drake, Andrew J.; Hessels, J. W. T.; Laher, Russ R.; Levitan, David B.; Lewis, Fraser; Mahabal, Ashish A.; Ofek, Eran O.; Prince, Thomas A.; Ransom, Scott M.; Roberts, Mallory S. E.; Russell, David M.; Sesar, Branimir; Surace, Jason A.; Tang, Sumin
    PSR J2129−0429 is a "redback" eclipsing millisecond pulsar binary with an unusually long 15.2 hr orbit. It was discovered by the Green Bank Telescope in a targeted search of unidentified Fermi gamma-ray sources. The pulsar companion is optically bright (mean m_R = 16.6 mag), allowing us to construct the longest baseline photometric data set available for such a system. We present 10 years of archival and new photometry of the companion from the Lincoln Near-Earth Asteroid Research Survey, the Catalina Real-time Transient Survey, the Palomar Transient Factory, the Palomar 60 inch, and the Las Cumbres Observatory Global Telescope. Radial velocity...

  18. Long-rising Type II supernovae from Palomar Transient Factory and Caltech Core-Collapse Project

    Taddia, F.; Sollerman, J.; Fremling, C.; Migotto, K.; Gal-Yam, A.; Armen, S.; Duggan, G.; Ergon, M.; Filippenko, A. V.; Fransson, C.; Hosseinzadeh, G.; Kasliwal, M. M.; Laher, R. R.; Leloudas, G.; Leonard, D. C.; Lunnan, R.; Masci, F. J.; Moon, D.-S.; Silverman, J. M.; Wozniak, P. R.
    Context. Supernova (SN) 1987A was a peculiar hydrogen-rich event with a long-rising (~ 84 d) light curve, stemming from the explosion of a compact blue supergiant star. Only a few similar events have been presented in the literature in recent decades. Aims. We present new data for a sample of six long-rising Type II SNe (SNe II), three of which were discovered and observed by the Palomar Transient Factory (PTF) and three observed by the Caltech Core-Collapse Project (CCCP). Our aim is to enlarge this small family of long-rising SNe II, characterizing their differences in terms of progenitor and explosion parameters....

  19. Long-rising Type II supernovae from Palomar Transient Factory and Caltech Core-Collapse Project

    Taddia, F.; Sollerman, J.; Fremling, C.; Migotto, K.; Gal-Yam, A.; Armen, S.; Duggan, G.; Ergon, M.; Filippenko, A. V.; Fransson, C.; Hosseinzadeh, G.; Kasliwal, M. M.; Laher, R. R.; Leloudas, G.; Leonard, D. C.; Lunnan, R.; Masci, F. J.; Moon, D.-S.; Silverman, J. M.; Wozniak, P. R.
    Context. Supernova (SN) 1987A was a peculiar hydrogen-rich event with a long-rising (~ 84 d) light curve, stemming from the explosion of a compact blue supergiant star. Only a few similar events have been presented in the literature in recent decades. Aims. We present new data for a sample of six long-rising Type II SNe (SNe II), three of which were discovered and observed by the Palomar Transient Factory (PTF) and three observed by the Caltech Core-Collapse Project (CCCP). Our aim is to enlarge this small family of long-rising SNe II, characterizing their differences in terms of progenitor and explosion parameters....

  20. An Intermediate Type Ia Supernova Between Normal And Super-Chandrasekhar

    Cao, Yi; Johansson, J.; Nugent, Peter E.; Goobar, A.; Nordin, Jakob; Kulkarni, S. R.; Cenko, S. Bradley; Fox, Ori; Kasliwal, Mansi M.; Fremling, C.; Amanullah, R.; Hsiao, E. Y.; Perley, D. A.; Bue, Brian D.; Masci, Frank J.; Lee, William H.; Chotard, Nicolas
    While recent observations provide evidence that super-Chandrasekhar Type Ia supernovae and at least a fraction of normal Type Ia supernovae probably originate from double-degenerate systems, these two subclasses show distinct characteristics observationally. Here we report an intermediate supernova iPTF13asv that may bridge this gap. On the one hand, similar to normal Type Ia supernovae, the over-luminous iPTF13asv follows the empirical relation between the peak magnitude, the lightcurve shape and its intrinsic color, and shows a near-IR secondary maximum like normal supernovae. On the other hand, similar to super-Chandrasekhar events, it has strong UV emission around maximum, low expansion velocities and persistent...

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