scholarly journals A Near-Infrared Spectral Sequence of Late M, L, and T Dwarfs

2003 ◽  
Vol 211 ◽  
pp. 389-392
Author(s):  
Michael C. Cushing ◽  
John T. Rayner ◽  
William D. Vacca
Keyword(s):  
Spectral Sequence ◽  
Emission Spectrum ◽  
Atomic Absorption ◽  
Near Infrared ◽  
Late Type ◽  
Medium Resolution ◽  
Infrared Spectral ◽  
Absorption Features ◽  
Initial Results

We present the initial results of a medium resolution, 0.8 to 4.2 μm spectroscopic survey of M, L, and T dwarfs. We have identified the most prominent molecular and atomic absorption features found in the spectra of these late-type dwarfs. We have also compared the spectra to a laboratory FeH emission spectrum and identified nearly 100 features common to the FeH spectrum and the dwarf spectra from 0.99 to 1.8 μm.

scholarly journals A Medium‐Resolution Near‐Infrared Spectral Library of Late‐Type Stars. I.

2004 ◽  
Vol 151 (2) ◽  
pp. 387-397 ◽  
Author(s):  
Valentin D. Ivanov ◽  
Marcia J. Rieke ◽  
Charles W. Engelbracht ◽  
Almudena Alonso‐Herrero ◽  
George H. Rieke ◽  
...  
Keyword(s):  
Near Infrared ◽  
Late Type ◽  
Spectral Library ◽  
Medium Resolution ◽  
Infrared Spectral

scholarly journals Classification by Photoelectric Measurements of Molecular Bands: Current Status and Future Prospects

1979 ◽  
Vol 47 ◽  
pp. 347-373
Author(s):  
Robert F. Wing
Keyword(s):  
Near Infrared ◽  
Narrow Band ◽  
Current Status ◽  
Two Dimensional ◽  
Future Prospects ◽  
Late Type ◽  
Classification Technique ◽  
Cool Stars ◽  
Infrared Spectral ◽  
Photoelectric Measurements

AbstractAs a classification technique, photoelectric narrow-band photometry is especially effective in the case of late-type spectra, in which molecular bands furnish the most sensitive criteria. Measurements of molecular bands with bandpasses of about 50 Å can be made very efficiently, and for normal stars they can be calibrated in terms of temperature and luminosity. In the case of normal late-type giants and supergiants, two-dimensional classifications can be obtained from measurements of TiO and CN; for very cool giants and for dwarfs it is useful siso to measure VO and CaH, respectively. All these molecules have bands in the red and near-infrared spectral regions, where cool stars are relatively bright and where photometric accuracy is highest.

scholarly journals Medium-Resolution Near-Infrared (2.15-2.35 micron) Spectroscopy of Late-Type Main-Sequence Stars

1995 ◽  
Vol 110 ◽  
pp. 2415 ◽  
Author(s):  
B. Ali ◽  
John S. Carr ◽  
D. L. Depoy ◽  
Jay A. Frogel ◽  
K. Sellgren
Keyword(s):  
Main Sequence ◽  
Near Infrared ◽  
Late Type ◽  
Main Sequence Stars ◽  
Medium Resolution

scholarly journals Off-Axis Cavity-Enhanced Absorption Spectroscopy of 14NH3 in Air Using a Gain-Switched Frequency Comb at 1.514 μm

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5217 ◽  
Author(s):  
Satheesh Chandran ◽  
Albert A. Ruth ◽  
Eamonn P. Martin ◽  
Justin K. Alexander ◽  
Frank H. Peters ◽  
...  
Keyword(s):  
Spectral Region ◽  
Near Infrared ◽  
Frequency Comb ◽  
Free Spectral Range ◽  
Detection Scheme ◽  
Enhanced Absorption ◽  
Cavity Enhanced Absorption Spectroscopy ◽  
Infrared Spectral ◽  
Ammonia Absorption ◽  
Absorption Features

A custom-designed gain-switched frequency comb (GSFC) source was passively coupled to a medium finesse (F ≈ 522) cavity in off-axis configuration for the detection of ammonia (14NH3) in static dry air. The absorption of ammonia was detected in the near infrared spectral region between 6604 and 6607 cm−1 using a Fourier transform detection scheme. More than 30 lines of the GSFC output (free spectral range 2.5 GHz) overlapped with the strongest ro-vibrational ammonia absorption features in that spectral region. With the cavity in off-axis configuration, an NH3 detection limit of ∼3.7 ppmv in 20 s was accomplished in a laboratory environment. The experimental performance of the prototype spectrometer was characterized; advantages, drawbacks and the potential for future applications are discussed.

scholarly journals Magnetic Fields Measured with the 10830 Å HeI Line

1971 ◽  
Vol 43 ◽  
pp. 279-288 ◽  
Author(s):  
J. Harvey ◽  
D. Hall
Keyword(s):  
Fine Structure ◽  
Magnetic Fields ◽  
Near Infrared ◽  
Active Regions ◽  
Field Measurements ◽  
Spectral Lines ◽  
Magnetic Field Measurements ◽  
Infrared Spectral ◽  
Polarity Reversals ◽  
Absorption Features

Several advantages of near infrared spectral lines for magnetic field measurements are listed. In particular, the 10830 Å multiplet of HeI is well suited for observations of chromospheric magnetic fields.New photoelectric spectroheliograms made with the 10830 Å line reveal a large amount of filamentary fine structure in active regions. This fine structure has important consequences on the interpretation of 10830 Å magnetograms. Except for an association of 10830 Å disk filaments with polarity reversals there is little correlation between absorption features and the 10830 Å longitudinal field. Comparisons of chromospheric and photospheric observations show that the chromospheric field is spatially more diffuse and weaker than the photospheric field.

Col-OSSOS: Investigating Outlying Surfaces within the Kuiper Belt's Neutral Coloured Objects

2021 ◽  
Author(s):  
Laura Buchanan ◽  
Megan Schwamb ◽  
Wesley Fraser ◽  
Michele Bannister ◽  
Michaël Marsset ◽  
...  
Keyword(s):  
Solar System ◽  
Near Infrared ◽  
Kuiper Belt ◽  
Outer Solar System ◽  
Kuiper Belt Object ◽  
Broadband Absorption ◽  
Colour Measurements ◽  
Infrared Spectral ◽  
Colour Distribution ◽  
Absorption Features

<p>Within the outer Solar System exists the Kuiper belt. This Kuiper belt is made up of many icy planetesimals, the remaining relics of planet-forming bodies that failed to evolve into a planet beyond Neptune. The smaller members of the Kuiper belt (with <em>r</em> mag > 22) generally show linear and featureless spectra. Additionally, due to the dimness of these objects observing their spectra can be particularly difficult. Therefore, broadband photometry is often used to characterise their surfaces. The broadband photometry can be used as a proxy for composition, as it provides enough information to characterise the optical and near-infrared spectral slopes ofthese Kuiper Belt Object (KBO) surfaces.</p> <p>The Colours of the Outer Solar System Origins Survey (Col-OSSOS, Schwamb et al., 2019) took near-simultaneous <em>g-</em>, <em>r-</em> and <em>J-band</em> broadband photometry of a sample of KBOs with unprecedented precision using the Gemini North telescope. As with previous colour surveys (e.g. Tegler et al., 2016), they showed abimodal colour distribution in optical / near-infrared colours for the dynamically ‘hot’ population. We split this colour distribution into the ‘neutral’ coloured population with <em>(</em><em>g−r</em><em>)</em> < 0.75 and the ‘red’ coloured populationwith <em>(</em><em>g−r</em><em>)</em> ≥ 0.75.</p> <p>The preciseness of the colour measurements of Col-OSSOS has allowed the identification of several KBOs with outlying surface colours. These objects separated out from the rest of the neutral cloud in <em>(</em><em>g−r</em><em>)</em> versus <em>(r−J</em><em>)</em> colours, with <em>(</em><em>g−r</em><em>)</em> colour near solar colour. Using the Gemini North telescope in Hawaii we have taken extra photometry in the <em>i</em><em>−</em> and <em>z−</em><em>bands</em> for three of these objects (2013 JE64, 2013 JR65 and 2014 UL225). These additional filter observations will allow us to identify any possible broadband absorption features on these object’s surfaces that may have caused their outlying surface colours. Asteroid interloper 2004 EW95 (Seccull et al., 2018), along with some Jupiter Trojans and C-type asteroids (Bus & Binzel, 2002; DeMeo & Carry,2013) have been shown to have similar near solar neutral surfaces. In this presentation we will report resultsof the <em>griz</em> photometry of 2013 JE64, 2013 JR65 and 2014 UL225. We will make comparisons between these results and the photometry of previously identified outlying KBOs and comment on any possible similarities.</p> <p><strong>References</strong></p> <p>Bus, S. J., & Binzel, R. P. 2002, Icarus, 158, 146<br />DeMeo, F. E., & Carry, B. 2013, Icarus, 226, 723<br />Schwamb, M. E., Bannister, M. T., Marsset, M., et al. 2019, ApJS, 243, 12<br />Seccull, T., Fraser, W. C., Puzia, T. H., Brown, M. E., & Schönebeck, F. 2018, ApJ, Letters, 855, L26<br />Tegler, S. C., Romanishin, W., Consolmagno, G. J., & J., S. 2016, AJ, 152, 210</p>

scholarly journals A Medium Resolution Near‐Infrared Spectral Atlas of O and Early‐B Stars

2005 ◽  
Vol 161 (1) ◽  
pp. 154-170 ◽  
Author(s):  
M. M. Hanson ◽  
R.‐P. Kudritzki ◽  
M. A. Kenworthy ◽  
J. Puls ◽  
A. T. Tokunaga
Keyword(s):  
Near Infrared ◽  
B Stars ◽  
Medium Resolution ◽  
Infrared Spectral

scholarly journals Medium-resolution Optical and Near-infrared Spectral Atlas of 16 2MASS-selected NIR-red Active Galactic Nuclei at z ∼ 0.3

2018 ◽  
Vol 238 (2) ◽  
pp. 37 ◽  
Author(s):  
Dohyeong Kim ◽  
Myungshin Im ◽  
Gabriela Canalizo ◽  
Minjin Kim ◽  
Ji Hoon Kim ◽  
...  
Keyword(s):  
Active Galactic Nuclei ◽  
Near Infrared ◽  
Galactic Nuclei ◽  
Medium Resolution ◽  
Infrared Spectral

scholarly journals MEDIUM RESOLUTION SPECTRAL LIBRARY OF LATE-TYPE STELLAR TEMPLATES IN NEAR-INFRARED BAND

2011 ◽  
Vol 44 (4) ◽  
pp. 125-134 ◽  
Author(s):  
Huynh Anh Nguyena Le ◽  
Won-Seok Kang ◽  
Soo-Jong Pak ◽  
Myung-Shin Im ◽  
Jeong-Eun Lee ◽  
...  
Keyword(s):  
Near Infrared ◽  
Late Type ◽  
Spectral Library ◽  
Infrared Band ◽  
Medium Resolution
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