Paschen Lines and the Reddening of the Radio Galaxy 3C 109

Rudy, R. J.; Puetter, R. C.; Mazuk, S.

doi:10.1086/300980

Cited by 34 publications

(40 citation statements)

References 17 publications

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“…NIRIS and its operation on the Lick 3 m telescope have also been described before (Rudy, Puetter, & Mazuk 1999). For these observations we used a 2 00 wide slit oriented north-south.…”

Section: Observationsmentioning

confidence: 99%

0.8–13 Micron Spectroscopy of V838 Monocerotis and a Model for Its Emission

Lynch

Rudy

Russell

et al. 2004

ApJ

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We report on the results of a number of infrared spectra (0.8-2.5, 2.1-4.6, and 3-14 m) of V838 Monocerotis, taken from a short time after discovery in 2002 January to about 14 months later, in early 2003. The spectrum evolved dramatically, changing from a quasi-photospheric stellar spectrum with weak atomic emission lines (some with P Cygni profiles) to one showing a wide range of deep absorption features indicative of a cool, extended atmosphere with a circumstellar dust shell. The early spectra showed lines of s-process elements, such as Sr ii and Ba i. The later spectra showed absorption by gaseous H 2 O, CO, AlO, TiO, SiO, SO 2 , OH, VO, and SH, as well as a complex of emission near 10 m reminiscent of silicate emission, with a central absorbing feature at 10:3 m. Thus, V838 Mon appears to be oxygen-rich. A simple, spherically symmetric model of the system involving a central star with a two-component expanding circumstellar shell is presented that is able to explain the major molecular features and spectral energy distribution in the object's late stages. The derived shell mass and distance are 0.04 M and 9.2 kpc, respectively.

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“…NIRIS and its operation on the Lick 3 m telescope have also been described before (Rudy, Puetter, & Mazuk 1999). For these observations we used a 2 00 wide slit oriented north-south.…”

Section: Observationsmentioning

confidence: 99%

0.8–13 Micron Spectroscopy of V838 Monocerotis and a Model for Its Emission

Lynch

Rudy

Russell

et al. 2004

ApJ

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“…For these data, the instrument employed was Aerospace Near-Infrared Imaging Spectrograph (NIRIS; Rudy, Puetter, & Mazuk 1999), a long-slit spectrograph that uses two channels to provide nearly continuous coverage between 0.8 and 2.5 lm. A beam splitter that switches from reflection to transmission at 1.38 lm separates the channels.…”

Section: Observationsmentioning

confidence: 99%

Near‐Infrared Spectrophotometry and the CO Emission in V2274 Cygni (Nova Cygni 2001 No. 1)

Rudy

Dimpfl

Lynch

et al. 2003

ApJ

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Infrared spectroscopy of V2274 Cygni (=Nova Cygni 2001 No. 1) is presented for two widely separated epochs, 17 and 370 days after discovery. In addition to the Paschen and Brackett series of H i, the early-time spectrum shows strong emission lines of C i and N i, fluorescently excited lines of O i, and emission from the first overtone of carbon monoxide. Because the initial data were probably acquired no more than 18 days after outburst, CO molecule formation occurred remarkably quickly in the dense, cool, carbon and oxygen rich ejecta. Rapid formation was also seen in NQ Vul, V842 Cen, and V705 Cas, three other novae in which first-overtone CO emission has been detected. Formation of the CO molecule may occur chemically in a process that requires H 2 as a precursor or directly through radiative association. The overtone emission of V2274 Cyg indicates a temperature of $2500 K. The vibrational levels show no obvious departures from thermal equilibrium, which may indicate high optical depths in the fundamental. A large 13 C/ 12 C ratio (0:83 AE 0:3) is also indicated by the observations, consistent with the fast CNO burning expected in novae explosions. By the time of the second epoch observations, the emission lines of the neutral C, N, and O had disappeared. He i 10830 was the dominant emission feature in the spectrum. In addition to the hydrogen lines, recombination features of He ii were also strong. The common nebular lines of [S iii] were seen but only two coronal line, [S viii] 9911 and [Si vi] 19645, were detected. The CO emission had disappeared, but a strong thermal dust component was present. The interstellar reddening for the system was found to be E(BÀV Þ ¼ 1:3. This extinction, together with the absolute magnitude derived from the rate of decline of the light curve, suggest a distance of $10.8 kpc. This places V2274 Cyg well out of the Galactic plane. The small number of novae with spectroscopic detections of carbon monoxide all have prominent C i lines, moderate speed classes and ejection velocities, exhibit marked dust formation events, and result from an explosion on a CO-type white dwarf. Based on these similarities, the spectrum of V2274 is proposed as a likely near-infrared spectral template for other novae that display carbon monoxide emission.

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“…All observations were made with the Aerospace Corporation's Near Infrared Imaging Spectrograph (Rudy, Puetter, & Mazuk 1999) on the University of California's Lick Observatory 3 m Shane Telescope. The spectrograph incorporates two separate channels, divided at 1.38 lm, to provide nearly continuous coverage between 0.8 and 2.5 lm.…”

Section: Observationsmentioning

confidence: 99%

“…The intrinsic flux ratios due to continuum fluorescence are 3.11 for the ratio of 0.8446 to 1.3164 lm and 0.066 for the ratio of 1.1287 to 1.3164 lm. A color excess value was also calculated from the observed hydrogen lines using the method of Rudy et al (1999). Here, the reddening of V4444 Sgr was measured by comparing the observed ratios of the hydrogen lines to Pa with their case B values from Storey & Hummer (1995) for a N e = 10 8 cm À3 and T e = 10 4 K gas.…”

Section: Light Curve Reddening and Distancementioning

confidence: 99%

Near-Infrared Spectroscopy of Nova Sagittarius 1999 (V4444 Sagittarii)

Venturini¹,

Rudy²,

Lynch³

et al. 2002

The Astronomical Journal

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We present 0.8-2.5 lm near-IR spectrophotometry of the very fast nova Nova Sagittarius 1999 (V4444 Sgr) taken 125 days after outburst. The emission-line spectrum of V4444 Sgr, with features ranging from C i to [Si ix] and [Si viii], exhibited perhaps the greatest spread of excitation for any single-epoch observation of a nova. However, two other novae, Nova Sagittarius 1992 No. 2 and Nova Aquila 1993, had spectra similar to V4444 Sgr between 0.8 and 1.4 lm, so such manifestations may not be uncommon. The continuum of V4444 Sgr showed a significant rise longward of 1.5 lm indicative of thermal emission from dust. The absence of any dust features in the light curve of V4444 Sgr suggests that we may have a relatively unobscured line of sight, or that some or all of the circumstellar dust was preexisting. The latter would indicate that V4444 Sgr is possibly a recurrent nova.

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Paschen Lines and the Reddening of the Radio Galaxy 3C 109

Cited by 34 publications

References 17 publications

0.8–13 Micron Spectroscopy of V838 Monocerotis and a Model for Its Emission

0.8–13 Micron Spectroscopy of V838 Monocerotis and a Model for Its Emission

Near‐Infrared Spectrophotometry and the CO Emission in V2274 Cygni (Nova Cygni 2001 No. 1)

Near-Infrared Spectroscopy of Nova Sagittarius 1999 (V4444 Sagittarii)

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