ARCES: an echelle spectrograph for the Astrophysical Research Consortium (ARC) 3.5m telescope

Wang, Shu-i; Hildebrand, R. H.; Hobbs, L. M.; Heimsath, S.; Kelderhouse, Gary; Loewenstein, R. F.; Lucero, S. C.; Rockosi, Constance M.; Sandford, Dale; Sundwall, Jeffrey L.; Thorburn, J. A.; York, Donald G.

doi:10.1117/12.461447

Cited by 78 publications

(14 citation statements)

References 8 publications

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“…With these parameters we find an active area of 1.7 km 2 . Using the derived upper limit of 3.8 km from Jewitt and Luu (2019) this results in a lower limit on the active fraction of ∼1%, consistent with Solar System comets (Sosa and Fernández 2011;Lis et al 2019). However, Jewitt and Luu (2019) argue that the nucleus is likely much smaller than this, perhaps only a few hundred meters in radius.…”

Section: Resultssupporting

confidence: 73%

Detection of a Water Tracer in Interstellar Comet 2I/Borisov

McKay

Cochran

Russo

et al. 2020

ApJL

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We present high spectral resolution optical spectra obtained with the ARCES instrument at Apache Point Observatory showing detection of the [O I]6300Å line in interstellar comet 2I/Borisov. We employ the observed flux in this line to derive an H 2 O production rate of (6.3±1.5)×10 26 mol s −1 . Comparing to previously reported observations of CN, this implies a CN/H 2 O ratio of ∼0.3-0.9%. The lower end of this range is consistent with the average value in comets, while the upper end is higher than the average value for Solar System comets, but still within the range of observed values. C 2 /H 2 O is normal or depleted depending on interpretation of recent results pertaining to C 2 . The dust-to-gas ratio is consistent with the normal value for Solar System comets. Using a simple sublimation model we estimate an H 2 O active area of 1.7 km 2 , which for current estimates for the size of Borisov suggests active fractions between 1-150%, consistent with values measured in Solar System comets. For the smallest size estimates our derived H 2 O production rates suggest Borisov may be hyperactive (> 100% of its surface active). However, these conclusions concerning active fraction are model dependent. More detailed characterization of 2I/Borisov, including compositional information and properties of the nucleus, are needed to fully interpret the observed H 2 O production rate.

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Section: Resultssupporting

confidence: 73%

Detection of a Water Tracer in Interstellar Comet 2I/Borisov

McKay

Cochran

Russo

et al. 2020

ApJL

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“…Seventeen epochs of optical spectra of HD 345439 were obtained using the Astrophysical Research Consortium Echelle Spectrograph (ARCES) on the Apache Point Observatory's (APO) 3.5 m telescope between 2012 September 2 and 2014 June 13 (see Table 1). ARCES (Wang et al 2003) is a high resolution, cross-dispersed visible light spectrograph 10 that obtains R ∼ 31,500 spectra between 3600 and 10000 Å. We observed bias, flat field, and ThAr lamp exposures for the echelle on every night.…”

Section: Optical Spectroscopymentioning

confidence: 87%

Characterizing the Rigidly Rotating Magnetosphere Stars Hd 345439 and Hd 23478

Wisniewski

Chojnowski

Davenport

et al. 2015

ApJ

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The SDSS III APOGEE survey recently identified two new σ Ori E type candidates, HD 345439 and HD 23478, which are a rare subset of rapidly rotating massive stars whose large (kGauss) magnetic fields confine circumstellar material around these systems. Our analysis of multi-epoch photometric observations of HD 345439 from the Kilodegree Extremely Little Telescope, Wide Angle Search for Planets, and ASAS surveys reveals the presence of a ∼0.7701 day period in each data set, suggesting the system is among the faster known σ Ori E analogs. We also see clear evidence that the strength of Hα, H I Brackett series lines, and He I lines also vary on a ∼0.7701 day period from our analysis of multi-epoch, multi-wavelength spectroscopic monitoring of the system from the APO 3.5 m telescope. We trace the evolution of select emission line profiles in the system, and observe coherent line profile variability in both optical and infrared H I lines, as expected for rigidly rotating magnetosphere stars. We also analyze the evolution of the H I Br-11 line strength and line profile in multi-epoch observations of HD 23478 from the SDSS-III APOGEE instrument. The observed periodic behavior is consistent with that recently reported by Sikora and collaborators in optical spectra.

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“…This large, uninterrupted spectral range allows for simultaneous observations of all three oxygen lines. More specifics for this instrument are discussed elsewhere (Wang et al, 2003;McKay et al, 2012McKay et al, , 2013.…”

Section: O I -Arces and Tull Coude Spectrographmentioning

confidence: 99%

Evolution of H2O, CO, and CO2 production in Comet C/2009 P1 Garradd during the 2011–2012 apparition

McKay

Cochran

DiSanti

et al. 2015

Icarus

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We present analysis of high spectral resolution NIR spectra of CO and H 2 O in comet C/2009 P1 (Garradd) taken during its 2011-2012 apparition with the CSHELL instrument on NASA's Infrared Telescope Facility (IRTF). We also present analysis of observations of atomic oxygen in comet Garradd obtained with the ARCES echelle spectrometer mounted on the ARC 3.5-meter telescope at Apache Point Observatory and the Tull Coude spectrograph on the Harlan J. Smith 2.7-meter telescope at McDonald Observatory. The observations of atomic oxygen serve as a proxy for H 2 O and CO 2 . We confirm the high CO abundance in comet Garradd and the asymmetry in the CO/H 2 O ratio with respect to perihelion reported by previous studies. From the oxygen observations, we infer that the CO 2 /H 2 O ratio decreased as the comet moved towards the Sun, which is expected based on current sublimation models.We also infer that the CO 2 /H 2 O ratio was higher pre-perihelion than postperihelion. We observe evidence for the icy grain source of H 2 O reported by several studies pre-perihelion, and argue that this source is significantly less abundant post-perihelion. Since H 2 O, CO 2 , and CO are the primary ices in comets, they drive the activity. We use our measurements of these important volatiles in an attempt to explain the evolution of Garradd's activity over the apparition.

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ARCES: an echelle spectrograph for the Astrophysical Research Consortium (ARC) 3.5m telescope

Cited by 78 publications

References 8 publications

Detection of a Water Tracer in Interstellar Comet 2I/Borisov

Detection of a Water Tracer in Interstellar Comet 2I/Borisov

Characterizing the Rigidly Rotating Magnetosphere Stars Hd 345439 and Hd 23478

Evolution of H2O, CO, and CO2 production in Comet C/2009 P1 Garradd during the 2011–2012 apparition

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