The Remote Observatories of the Southeastern Association for Research in Astronomy (SARA)

Keel, William C.; Oswalt, Terry D.; Mack, Peter; Henson, G. D.; Hillwig, Todd C.; Batcheldor, D.; Berrington, Robert C.; Pree, C. G. De; Hartmann, D. H.; Leake, M. A.; Licandro, J.; Murphy, B. W.; Webb, J. R.; Wood, M. A.

doi:10.1088/1538-3873/129/971/015002

Cited by 52 publications

(31 citation statements)

References 21 publications

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“…We carry out quasi-simultaneous optical observations for five objects 4 with the Southern Association for Research in Astronomy (SARA, Keel et al 2017) consortium's 1.0 m, 0.96 m and 0.6 m telescopes respectively located at la Roque de los Muchachos Observatory, Canary Islands (SARA-ORM), at Kitt Peak National Observatory, Arizona (SARA-KP) and at Cerro-Tololo, Chile (SARA-CT). We obtain our observations using the Bessel BVRI filters mounted on SARA-ORM and SARA-KP, and the SDSS griz filters mounted on SARA-CT.…”

Section: Saramentioning

confidence: 99%

NuSTAR Perspective on High-redshift MeV Blazars

Marcotulli

Paliya

Ajello

et al. 2020

ApJ

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With bolometric luminosities exceeding 10 48 erg s −1 , powerful jets and supermassive black holes at their center, MeV blazars are some of the most extreme sources in the Universe. Recently, the Fermi-Large Area Telescope detected five new γ-ray emitting MeV blazars beyond redshift z = 3.1. With the goal of precisely characterizing the jet properties of these extreme sources, we started a multiwavelength campaign to follow them up with joint NuSTAR, Swift and SARA observations. We observe six high-redshift quasars, four of them belonging to the new γ-ray emitting MeV blazars. Thorough X-ray analysis reveals spectral flattening at soft X-ray for three of these objects. The source NVSS J151002+570243 also shows a peculiar re-hardening of the X-ray spectrum at energies E > 6 keV. Adopting a one-zone leptonic emission model, this combination of hard X-rays and γ-rays enables us to determine the location of the Inverse Compton peak and to accurately constrain the jet characteristics. In the context of the jet-accretion disk connection, we find that all six sources have jet powers exceeding accretion disk luminosity, seemingly validating this positive correlation even beyond z > 3. Our six sources are found to have 10 9 M ⊙ black holes, further raising the space density of supermassive black holes in the redshift bin z = [3, 4].

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Section: Saramentioning

confidence: 99%

NuSTAR Perspective on High-redshift MeV Blazars

Marcotulli

Paliya

Ajello

et al. 2020

ApJ

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“…These offset values are listed in Table 6 for the three stars observed with the SARA telescopes. Details of the detectors are given by Keel et al (2017). We estimate the uncertainties in these offset values to be ±0.01 to ±0.02 mag.…”

Section: Appendix I: Combining the Multi-telescope Observationsmentioning

confidence: 99%

Variability in Proto-planetary Nebulae. VI. Multitelescope Light Curve Studies of Several Medium-bright (V = 13–15), Carbon-rich Objects

Hrivnak¹,

Henson²,

Hillwig³

et al. 2019

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We present ten years of new photometric monitoring of the light variability of five evolved stars with strong mid-infrared emission from surrounding dust. Three are known carbon-rich proto-planetary nebulae (PPNe) with F−G spectral types; the nature of the other two was previously unknown. For the three PPNe, we determine or refine the pulsation periods of IRAS 04296+3429 (71 days), 06530−0213 (80 days), and 23304+6147 (84 days). A secondary period was found for each, with a period ratio P 2 /P 1 of 0.9. The light variations are small, 0.1−0.2 mag. These are similar to values found in other PPNe. The other two are found to be giant stars. IRAS 09296+1159 pulsates with a period of only 47 days but reaches pulsational light variations of 0.5 mag. Supplemental spectroscopy reveals the spectrum of a CH carbon star. IRAS 08359−1644 is a G1 III star that does not display pulsational variability; rather, it shows non-periodic decreases of brightness of up to 0.5 mag over this ten-year interval. These drops in brightness are reminiscent of the light curves of R Corona Borealis variables, but with much smaller decreases in brightness, and are likely due to transient dust obscuration. Its SED is very similar to that of the unusual oxygen-rich giant star HDE 233517, which possesses midinfrared hydrocarbon emission features. These two non-PPNe turn out to members of the rare group of giant stars with large mid-infrared excesses due to dust, objects which presumably have interesting evolutionary histories.

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“…In addition to the UA 0.4m telescope, two telescopes operated by the Southeastern Association for Research in Astronomy (SARA) were used for the observations of SN 2017eaw: the SARA-KP 0.96-m telescope at Kitt Peak, Arizona, and the SARA-RM (formerly Jacobus Kapteyn) 1.0-m telescope at the Roque de los Muchachos on La Palma, the Canary Islands. The SARA facilities are described by Keel et al (2017) and are used remotely. Table 1 summarizes the CCDs, pixel scales, and other characteristics of the instruments used and of the images obtained.…”

Section: Observationsmentioning

confidence: 99%

BVRI photometry of the classic Type II-P supernova 2017eaw in NGC 6946: d 3 to d 594

Buta

Keel

2019

Monthly Notices of the Royal Astronomical Society

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Broadband BV RI light curves of SN 2017eaw in NGC 6946 reveal the classic elements of a Type II-P supernova. The observations were begun on 16 May 2017 (UT), approximately 1 day after the discovery was announced, and the photometric monitoring was carried out over a period of nearly 600 days. The light curves show a well-defined plateau and an exponential tail which curves slightly at later times. An approximation to the bolometric light curve is derived and used to estimate the amount of 56 Ni created in the explosion; from various approaches described in the literature, we obtain M( 56 Ni) = 0.115 −0.022 +0.027 M ⊙ . We also estimate that 43% of the bolometric flux emitted during the plateau phase is actually produced by the 56 Ni chain. Other derived parameters support the idea that the progenitor was a red supergiant.

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The Remote Observatories of the Southeastern Association for Research in Astronomy (SARA)

Cited by 52 publications

References 21 publications

NuSTAR Perspective on High-redshift MeV Blazars

NuSTAR Perspective on High-redshift MeV Blazars

Variability in Proto-planetary Nebulae. VI. Multitelescope Light Curve Studies of Several Medium-bright (V = 13–15), Carbon-rich Objects

BVRI photometry of the classic Type II-P supernova 2017eaw in NGC 6946: d 3 to d 594

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