scholarly journals The Structure of the HH39 Region

1987 ◽  
Vol 115 ◽  
pp. 340-341
Author(s):  
J. R. Walsh
Keyword(s):  
High Resolution ◽  
Radial Velocity ◽  
Proper Motion ◽  
High Velocity ◽  
Velocity Structure ◽  
The Other ◽  
Emission Lines ◽  
High Resolution Spectroscopy ◽  
Bow Shocks ◽  
Hh Objects

HH39 is the group of Herbig-Haro (HH) objects associated with the young semi-stellar object R Monocerotis (R Mon) and the variable reflection nebula NGC 2261. An R CCD frame and a B prime focus plate of the region show a filament connecting NGC 2261 with HH39, confirming the association between R Mon and the HH objects. This filament is probably composed of emission material. The southern knot in HH39 has brightened over the last 20 years; its proper motion has been determined and is similar to that of the other knots. A total of 8 knots can be distinguished in HH39 surrounded by diffuse nebulosity. High resolution spectroscopy of the Hα and [N II] emission lines shows the spatial variation of the radial velocity structure over the largest knots (HH39 A and C). Distinct differences in excitation and velocity structure between the knots are apparent. The observations are compatible with the knots being high velocity ejecta from R Mon, decelerated by interaction with ambient material and with bow shocks on their front surfaces.

scholarly journals HIGH-RESOLUTION SPECTROSCOPY OF THE B[e] STAR MWC 645

2021 ◽  
Vol 34 ◽  
pp. 59-64
Author(s):  
A.S. Nodyarov ◽  
A.S. Miroshnichenko ◽  
S.A. Khokhlov ◽  
S.V. Zharikov ◽  
N. Manset ◽  
...  
Keyword(s):  
High Resolution ◽  
Radial Velocity ◽  
Emission Line ◽  
Spectroscopic Data ◽  
Emission Lines ◽  
Absorption Lines ◽  
High Resolution Spectroscopy ◽  
Cool Component ◽  
Spectroscopic Observations ◽  
First Time

Optical high-resolution spectroscopic observations of the emission-line star MWC645 are presented. The spectrum exhibits strong variable double-peaked Balmer emission lines as well as low-excitation emission lines of FeII, [FeII], and [OI] which are signatures of the B[e] phenomenon, while lines of helium have not been found. In addition to the emission lines, for the first time we identified absorption lines of neutral metals (e.g., LiI 6708  A, CaI 6717 A, and a number of FeI and TiI lines) that indicate the presence of a cool component in the system. The heliocentric radial velocity measured in our best spectrum was found to be −65.1±1.0 kms −1 for the emission lines and −23.2±0.4 kms −1 for the absorption lines. Using a combination of photometric and spectroscopic data as well as the Gaia EDR3 distance (D=6.5±0.9 kpc), we disentangled the component contributions and estimated their temperatures and luminosities (∼15000 K and ∼4000 K, log L/L ? = 3.8±0.2 and 2.8±0.2 for the hot and cool component, respectively).

scholarly journals High Resolution Spectroscopy As a Tool for Luminosity Calibration

2002 ◽  
Vol 12 ◽  
pp. 676-679
Author(s):  
Ruth C. Peterson
Keyword(s):  
High Resolution ◽  
Reasonable Agreement ◽  
Empirical Relationship ◽  
Model Atmosphere ◽  
Stellar Mass ◽  
Physical Basis ◽  
Emission Lines ◽  
High Resolution Spectroscopy ◽  
Chromospheric Emission ◽  
Advance Knowledge

AbstractRecent results are reviewed for two methods of luminosity calibration based on high-resolution spectroscopy. The first relies onTeff/loggdeterminations from model-atmosphere analyses based on high-resolution spectra. This method is physically well founded but operationally demanding, and requires advance knowledge of stellar mass. The second, W-B, stems from the empirical relationship between luminosity and the width of chromospheric emission lines first established by Wilson and Bappu. Its physical basis is only partially understood, however, and the calibration depends on stellar metallicity and on the choice of lines.BothTeff/loggand W-B easily distinguish cool dwarfs from cool giants. Generally reasonable agreement is found between distances derived from Hipparcos parallaxes and those inferred from the loggvalues derived for nearby dwarfs with relatively well-known Hipparcos parallaxes, σ(π)/π < 0.2. Constraining Hipparcos parallaxes star-by-star is not possible at present. Improvements are suggested for both approaches.

scholarly journals Filtered CCD images of southern Herbig-Haro objects

1987 ◽  
Vol 122 ◽  
pp. 189-190
Author(s):  
B. Whitmore ◽  
D.H.M. Cameron ◽  
R.F. Warren-Smith
Keyword(s):  
High Velocity ◽  
Optical Emission ◽  
Emission Lines ◽  
Ccd Cameras ◽  
Hh Objects

It is currently believed that Herbig-Haro (HH) objects are a consequence of a high-velocity (up to at least 200 km s−1) outflow of material from a young embedded star. These flows can often be detected by deep observations of optical emission lines using CCD cameras.

High Velocity Spectroscopic Binary Orbits from Photoelectric Radial Velocities: BD+20 5152, a Possible Triple System

2010 ◽  
Vol 19 (3-4) ◽  
Author(s):  
J. Sperauskas ◽  
A. Bartkevičius ◽  
R. P. Boyle ◽  
V. Deveikis
Keyword(s):  
Radial Velocity ◽  
Proper Motion ◽  
High Velocity ◽  
Triple System ◽  
Mass Velocity ◽  
Center Of Mass ◽  
Primary Component ◽  
Eccentric Orbit ◽  
Velocity Measurements ◽  
Spectroscopic Binary

AbstractThe spectroscopic orbit of a high proper motion star, BD+20 5152, is calculated from 34 CORAVEL-type radial velocity measurements. The star has a slightly eccentric orbit with a period of 5.70613 d, half-amplitude of 47.7 km/s and eccentricity of 0.049. The center-of-mass velocity of the system is -24.3 km/s. BD+20 5152 seems to be a triple system consisting of a G8 dwarf as a primary component and of two K6-M0 dwarfs as secondary and tertiary components. This model is based on the analysis of its UBVRI and JHK magnitudes. According to the SuperWASP photometry, spots on the surface of the primary are suspected. The excessive brightness in the Galex FUV and NUV magnitudes and a non-zero eccentricity suggest the age of this system to be less than 1 Gyr.

scholarly journals High-resolution spectroscopy of the high-velocity hot post-AGB star LS III +52°24 (IRAS 22023+5249)

2012 ◽  
pp. no-no ◽  
Author(s):  
G. Sarkar ◽  
D. A. García-Hernández ◽  
M. Parthasarathy ◽  
A. Manchado ◽  
P. García-Lario ◽  
...  
Keyword(s):  
High Resolution ◽  
High Velocity ◽  
High Resolution Spectroscopy

scholarly journals A weak spectral signature of water vapour in the atmosphere of HD 179949 b at high spectral resolution in the L band

2020 ◽  
Vol 494 (1) ◽  
pp. 108-119 ◽  
Author(s):  
Rebecca K Webb ◽  
Matteo Brogi ◽  
Siddharth Gandhi ◽  
Michael R Line ◽  
Jayne L Birkby ◽  
...  
Keyword(s):  
High Resolution ◽  
Radial Velocity ◽  
Semimajor Axis ◽  
Spectral Lines ◽  
Lapse Rate ◽  
High Spectral Resolution ◽  
High Resolution Spectroscopy ◽  
Spectral Signature ◽  
Orbital Inclination ◽  
L Band

ABSTRACT High-resolution spectroscopy ($R\, \geqslant \, 20\, 000$) is currently the only known method to constrain the orbital solution and atmospheric properties of non-transiting hot Jupiters. It does so by resolving the spectral features of the planet into a forest of spectral lines and directly observing its Doppler shift while orbiting the host star. In this study, we analyse VLT/CRIRES ($R=100\, 000$) L-band observations of the non-transiting giant planet HD 179949 b centred around 3.5 ${\mu {m}}$. We observe a weak (3.0σ, or S/N = 4.8) spectral signature of H2O in absorption contained within the radial velocity of the planet at superior-conjunction, with a mild dependence on the choice of line list used for the modelling. Combining this data with previous observations in the K band, we measure a detection significance of 8.4 σ for an atmosphere that is most consistent with a shallow lapse-rate, solar C/O ratio, and with CO and H2O being the only major sources of opacity in this wavelength range. As the two sets of data were taken 3 yr apart, this points to the absence of strong radial-velocity anomalies due, e.g. to variability in atmospheric circulation. We measure a projected orbital velocity for the planet of KP = (145.2 ± 2.0) km s−1 (1σ) and improve the error bars on this parameter by ∼70 per cent. However, we only marginally tighten constraints on orbital inclination ($66.2^{+3.7}_{-3.1}$ deg) and planet mass ($0.963^{+0.036}_{-0.031}$ Jupiter masses), due to the dominant uncertainties of stellar mass and semimajor axis. Follow ups of radial-velocity planets are thus crucial to fully enable their accurate characterization via high-resolution spectroscopy.

scholarly journals Spherically Symmetric Kinematic Modelling of Planetary Nebulae

1993 ◽  
Vol 155 ◽  
pp. 374-374
Author(s):  
C. Diesch ◽  
M. Grewing
Keyword(s):  
High Resolution ◽  
Radial Velocity ◽  
Symmetric Functions ◽  
Emission Lines ◽  
List Type ◽  
Line Broadening ◽  
Radial Velocity Component ◽  
Spatially Resolved ◽  
Kinematic Modelling ◽  
Single Emission

High resolution two-dimensional long slit spectra of NGC 7009, NGC 3242, IC 2448 and TC 1 in the Hα(6565 Å), OIII(5007 Å) and NII(6584 Å) emission lines have been used as input to determine radial velocity gradients in PNe by fitting calculated high resolution spatially resolved spectral structures of single emission lines. Contributions to the Doppler structure of emission lines taken into account are the global expansion of the PN shell and thermal line broadening due to temperatures of some 104 K. This model is based on two parametrized empirically chosen spherical symmetric functions: 1.A empirical two parameter density function ρ(r).2.A linear radial velocity component function ν(r).

scholarly journals Morphological and kinematical analysis of the planetary nebula Hu 1-2 and its irradiated bow-shocks

2011 ◽  
Vol 7 (S283) ◽  
pp. 440-441
Author(s):  
Luis F. Miranda ◽  
Mónica Blanco ◽  
Martín A. Guerrero ◽  
Angels Riera
Keyword(s):  
High Resolution ◽  
High Velocity ◽  
Planetary Nebula ◽  
Narrow Band ◽  
Central Star ◽  
Kinematical Analysis ◽  
Near Ir ◽  
Bow Shocks

AbstractWe present narrow-band optical and near-IR images, and high-resolution long-slit spectra of the planetary nebula Hu 1-2 that allow us to make a detailed description of its unusual morphology and internal kinematics. The data also reveal that the ansae of Hu 1-2 probably represent bow-shocks associated to high velocity outflows that are irradiated from the central star.

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