- ID:
- ivo://CDS.VizieR/J/AJ/160/235
- Title:
- Optical photometry and RVs of TOI-481b and TOI-892b
- Short Name:
- J/AJ/160/235
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the discovery of two new 10 day period giant planets from the Transiting Exoplanet Survey Satellite mission, whose masses were precisely determined using a wide diversity of ground-based facilities. TOI-481b and TOI-892b have similar radii (0.99{+/-}0.01R_Jup_ and 1.07{+/-}0.02R_Jup_, respectively), and orbital periods (10.3311days and 10.6266days, respectively), but significantly different masses (1.53{+/-}0.03M_Jup versus 0.95{+/-}0.07M_Jup_, respectively). Both planets orbit metal-rich stars ([Fe/H]=+0.26{+/-}0.05dex and [Fe/H]=+0.24{+/-}0.05 for TOI-481 and TOI-892, respectively) but at different evolutionary stages. TOI-481 is a M_*_=1.14{+/-}0.02M_{odot}_, R_*_=1.66{+/-}0.02R_{odot}_ G-type star (Teff=5735{+/-}72K), that with an age of 6.7Gyr, is in the turn-off point of the main sequence. TOI-892 on the other hand, is a F-type dwarf star (Teff=6261{+/-}80K), which has a mass of M_*_=1.28{+/-}0.03M_{odot}_ and a radius of R_*_=1.39{+/-}0.02R_{odot}_. TOI-481b and TOI-892b join the scarcely populated region of transiting gas giants with orbital periods longer than 10days, which is important to constrain theories of the formation and structure of hot Jupiters.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/758/25
- Title:
- Optical properties of WISE galaxies
- Short Name:
- J/ApJ/758/25
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use a dense, complete redshift survey, the Smithsonian Hectospec Lensing Survey (SHELS), covering a 4deg^2^ region of a deep imaging survey, the Deep Lens Survey (DLS), to study the optical spectral properties of Wide-field Infrared Survey Explorer (WISE) 22{mu}m selected galaxies. Among 507 WISE 22{mu}m selected sources with (S/N)_22{mu}m_>=3 ({approx}S_22{mu}m_>~2.5mJy), we identify the optical counterparts of 481 sources (~98%) at R<25.2 in the very deep, DLS R-band source catalog. Among them, 337 galaxies at R<21 have SHELS spectroscopic data. Most of these objects are at z<0.8. The infrared (IR) luminosities are in the range 4.5x10^8^(L_{sun}_)<~L_IR_<~5.4x10^12^(L_{sun}_). Most 22{mu}m selected galaxies are dusty star-forming galaxies with a small (<1.5) 4000{AA} break. The stacked spectra of the 22 {mu}m selected galaxies binned in IR luminosity show that the strength of the [O III] line relative to H{beta} grows with increasing IR luminosity. The optical spectra of the 22{mu}m selected galaxies also show that there are some (~2.8%) unusual galaxies with very strong [Ne III] {lambda}3869, 3968 emission lines that require hard ionizing radiation such as active galactic nuclei (AGNs) or extremely young massive stars. The specific star formation rates (sSFRs) derived from the 3.6 and 22{mu}m flux densities are enhanced if the 22{mu}m selected galaxies have close late-type neighbors. The sSFR distribution of the 22{mu}m selected galaxies containing AGNs is similar to the distribution for star-forming galaxies without AGNs. We identify 48 dust-obscured galaxy candidates with large (>~1000) mid-IR to optical flux density ratio. The combination of deep photometric and spectroscopic data with WISE data suggests that WISE can probe the universe to z~2.
- ID:
- ivo://CDS.VizieR/J/ApJ/840/97
- Title:
- Optical reverberation mapping campaign of 5 AGNs
- Short Name:
- J/ApJ/840/97
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first results from an optical reverberation mapping campaign executed in 2014 targeting the active galactic nuclei (AGNs) MCG+08-11-011, NGC 2617, NGC 4051, 3C 382, and Mrk 374. Our targets have diverse and interesting observational properties, including a "changing look" AGN and a broad-line radio galaxy. Based on continuum-H{beta} lags, we measure black hole masses for all five targets. We also obtain H{gamma} and HeII{lambda}4686 lags for all objects except 3C 382. The HeII{lambda}4686 lags indicate radial stratification of the BLR, and the masses derived from different emission lines are in general agreement. The relative responsivities of these lines are also in qualitative agreement with photoionization models. These spectra have extremely high signal-to-noise ratios (100-300 per pixel) and there are excellent prospects for obtaining velocity-resolved reverberation signatures.
- ID:
- ivo://CDS.VizieR/J/ApJ/875/85
- Title:
- Optical search for SNRs in NGC6946 with WIYN & GMOS
- Short Name:
- J/ApJ/875/85
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The relatively nearby spiral galaxy NGC 6946 is one of the most actively star-forming galaxies in the local universe. Ten supernovae (SNe) have been observed since 1917, and hence NGC 6946 surely contains a large number of supernova remnants (SNRs). Here we report a new optical search for these SNRs using narrowband images obtained with the WIYN telescope. We identify 147 emission nebulae as likely SNRs, based on elevated [SII]:H{alpha} ratios compared to HII regions. We have obtained spectra of 102 of these nebulae with Gemini North-GMOS; of these, 89 have [SII]:H{alpha} ratios greater than 0.4, the canonical optical criterion for identifying SNRs. There is very little overlap between our sample and the SNR candidates identified by Lacey+ (1997ApJS..109..417L) from radio data. Also, very few of our SNR candidates are known X-ray sources, unlike the situation in some other galaxies such as M33 and M83. The emission-line ratios, e.g., [NII]:H{alpha}, of the candidates in NGC 6946 are typical of those observed in SNR samples from other galaxies with comparable metallicity. None of the candidates observed in our low-resolution spectra show evidence of anomalous abundances or significant velocity broadening. A search for emission at the sites of all the historical SNe in NGC 6946 resulted in detections for only two: SN 1980K and SN 2004et. Spectra of both show very broad, asymmetric line profiles, consistent with the interaction between SN ejecta and the progenitor star's circumstellar material, as seen in late spectra from other core-collapse SNe of similar age.
- ID:
- ivo://CDS.VizieR/J/AZh/84/714
- Title:
- Optical spectral variability of BD+48 1220
- Short Name:
- J/AZh/84/714
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Based on high-resolution observations (R=60000 and 75000), we have studied the optical spectral variability of the star BD+48 1220, identified with the IR-source IRAS 05040+4820. We have measured the equivalent widths of numerous absorption lines of neutral atoms and ions at wavelengths from 4500 to 6760{AA}, as well as the corresponding radial velocities. We use model atmospheres to determine the effective temperature Teff=7900K, surface gravity log g=0.0, microturbulence velocity xi_t_=6.0, and the abundances for 16 elements. The star's metallicity differs little from the solar value: [Fe/H]=-0.10dex. The main peculiarity of the chemical composition of the star is a large He-excess, derived from the HeI 5876{AA} absorption, [He/H]=+1.04, and the equally large O-excess, [O/Fe]=+0.72dex. The C-excess is small, [C/Fe]=+0.09dex, and the ratio [C/O]<=1. We obtained a revised relation for the light-metal abundances: [Na/Fe]=+0.87 with [Mg/Fe]=-0.31. The barium abundance is low, [Ba/Fe]=-0.84. The radial velocity of the star measured from photospheric absorption lines over three years of observations varies in the interval V_{sun}_=-(7-15)km/s. Time variable differential line shifts have been revealed. The entire set of available data (the luminosity Mv~-5mag, velocity V_lsr_~-20km/s, metallicity [Fe/H]=-0.10, and peculiarities of the optical spectrum and chemical composition) confirms the status of BD+48 1220 as a post-AGB star with He- and O-excesses belonging to the Galactic disk.
- ID:
- ivo://CDS.VizieR/J/AZh/83/265
- Title:
- Optical spectral variability of IRAS 20508+2011
- Short Name:
- J/AZh/83/265
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Based on high-resolution spectra we revealed variability of the optical spectrum of the cool star identified with the IR source IRAS 20508+2011. Over the five years of our observations, the radial velocity derived from photospheric absorption lines varied in the interval V_r_=15-30km/s. In the same time, the H(alpha) profile varied from an intense bell-shaped emission line with a small absorption to 2-peaked emission with a central absorption feature below the continuum level. At all but one epoch, the positions of the metallic photospheric lines were systematically shifted relative to the H(alpha) emission: Delta V_r_=V_r_(met)-V_r_(Halpha,emis)~-23km/s. The NaD doublet lines shown a complex profile with broad (half-width about 120km/s) emission and photospheric absorption, as well as an interstellar component. We used model atmospheres to determine the physical parameters and chemical composition of the star's atmosphere: Teff=4800K, logg=1.5, Vt=4.0km/s and metallicity [Fe/H]=-0.36. We detected overabundances of oxygen [O/Fe]=+1.79 (with the ratio [C/O]~-0.9), and alpha-process elements, as well as a deficit of heavy metals. The totality of the parameters suggests that the optical component of IRAS 20508+2011 is an "O-rich" AGB star with luminosity M_v_~-3mag that is close to its evolution transition to the post-AGB stage.
- ID:
- ivo://CDS.VizieR/J/A+A/622/A45
- Title:
- 1995-2000 optical spectra of CH Cyg
- Short Name:
- J/A+A/622/A45
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- CH Cyg is one of the most studied symbiotic stars. Its properties, however, are still not well known. Two main periods, about 15 years and 750-days, are known in the photometric and spectroscopic variations, and two models are proposed for these origins. One is a binary system with an orbital period of 15 years consisting of a hot component and pulsating red giant with a 750-day period. The other is a triple system consisting of an inner symbiotic binary with an orbital period of about 750-days and third component with an orbital period of 15 years. Several active stages have been observed since the 1970s during which the object brightened up by {Delta}U=3-5mag and prominent emission lines appeared. Large mass outflows were observed at some active stages. The spectral variation of CH Cyg has been monitored at Asiago Observatories to understand the problems mentioned above. We have analysed spectra obtained in the time period from 1995 to 2004 which covers an active stage during the years 1998-2000. High- and low-resolution optical spectra obtained at the Asiago Observatories are used. Narrow absorption lines of FeI, CrI, TiI, and so on appeared in 1998 at an early phase of the active stage. These lines are clearly distinguished from those of the M-type giant and are typically found on the spectrum of early A-type dwarfs. They were redshifted by about 30km/s, with respect to the absorption lines of the M-type giant. Assuming that their radial velocities represent the orbital motion of the hot component, its semi-amplitude is estimated to be 37.0+/60.5km/s.
- ID:
- ivo://CDS.VizieR/J/A+A/338/1066
- Title:
- Optical Spectra of DENIS Brown Dwarf Candidate
- Short Name:
- J/A+A/338/1066
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Optical spectra for candidate brown dwarfs from the DENIS Mini-survey are provided. These are the spectra used to in Figure 1 of the paper.
- ID:
- ivo://CDS.VizieR/J/A+A/335/510
- Title:
- Optical spectra of 7 hot UV bright stars in GC
- Short Name:
- J/A+A/335/510
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained medium-resolution spectra of seven UV-bright stars discovered on images of four southern globular clusters obtained with the Ultraviolet Imaging Telescope (UIT). Effective temperatures, surface gravities and helium abundances are derived from LTE and non-LTE model atmosphere fits. Three of the stars have sdO spectra, including M4-Y453 (T_eff_=58800K, logg=5.15), NGC 6723-III60 (T_eff_=40600K, logg=4.46) and NGC 6752-B2004 (T_eff_=37000K, logg=5.25). All seven stars lie along either post-extended horizontal branch (EHB) or post-early AGB evolutionary tracks. The post-early AGB stars show solar helium abundances, while the post-EHB stars are helium deficient, similar to their EHB progenitors. Based on observations collected at the European Southern Observatory (ESO No 57.E-0101)
- ID:
- ivo://CDS.VizieR/J/A+A/561/A137
- Title:
- Optical spectra of IGR J21343+4738
- Short Name:
- J/A+A/561/A137
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Present X-ray missions are regularly discovering new X-ray and gamma-ray sources. The identification of their counterparts at other wavelengths allows us to determine their nature. The main goal of this work is to determine the properties of the optical counterpart to the INTEGRAL source IGR J21343+4738, and to study its long-term optical variability. Although its nature as a Be/X-ray binary has been suggested, little is known about its physical parameters. We have been monitoring IGR J21343+4738 since 2009 in the optical band. We present BVRI optical photometric and spectroscopic observations covering the wavelength band 4000-7500{AA}. The photometric data allowed us to derive the colour excess E(B-V) and estimate the distance. The blue-end spectra were used to determine the spectral type of the optical companion, while the spectra around the Halpha line allowed us to study the long-term structural changes in the circumstellar disc.
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