scholarly journals CS Cha B: A disc-obscured M-type star mimicking a polarised planetary companion

2020 ◽  
Vol 640 ◽  
pp. L12
Author(s):  
S. Y. Haffert ◽  
R. G. van Holstein ◽  
C. Ginski ◽  
J. Brinchmann ◽  
I. A. G. Snellen ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
Near Infrared ◽  
Type Star ◽  
Atmospheric Models ◽  
Planetary Mass ◽  
Medium Resolution ◽  
Low Mass ◽  
Integral Field Spectrograph ◽  
Integral Field

Context. Direct imaging provides a steady flow of newly discovered giant planets and brown dwarf companions. These multi-object systems can provide information about the formation of low-mass companions in wide orbits and/or help us to speculate about possible migration scenarios. Accurate classification of companions is crucial for testing formation pathways. Aims. In this work we further characterise the recently discovered candidate for a planetary-mass companion CS Cha b and determine if it is still accreting. Methods. MUSE is a four-laser-adaptive-optics-assisted medium-resolution integral-field spectrograph in the optical part of the spectrum. We observed the CS Cha system to obtain the first spectrum of CS Cha b. The companion is characterised by modelling both the spectrum from 6300 Å to 9300 Å and the photometry using archival data from the visible to the near-infrared (NIR). Results. We find evidence of accretion and outflow signatures in Hα and OI emission. The atmospheric models with the highest likelihood indicate an effective temperature of 3450 ± 50 K with a log g of 3.6 ± 0.5 dex. Based on evolutionary models, we find that the majority of the object is obscured. We determine the mass of the faint companion with several methods to be between 0.07 M⊙ and 0.71 M⊙ with an accretion rate of Ṁ = 4 × 10−11±0.4 M⊙ yr−1. Conclusions. Our results show that CS Cha B is most likely a mid-M-type star that is obscured by a highly inclined disc, which has led to its previous classification using broadband NIR photometry as a planetary-mass companion. This shows that it is important and necessary to observe over a broad spectral range to constrain the nature of faint companions.

scholarly journals Strong Hα emission and signs of accretion in a circumbinary planetary mass companion from MUSE

2020 ◽  
Vol 638 ◽  
pp. L6 ◽  
Author(s):  
Simon C. Eriksson ◽  
Rubén Asensio Torres ◽  
Markus Janson ◽  
Yuhiko Aoyama ◽  
Gabriel-Dominique Marleau ◽  
...  
Keyword(s):  
Field Mode ◽  
Planetary Mass ◽  
Very Large Telescope ◽  
Medium Resolution ◽  
Younger Age ◽  
Verification Time ◽  
Hα Emission ◽  
Low Mass ◽  
Integral Field Spectrograph ◽  
Integral Field

Context. Intrinsic Hα emission can be advantageously used to detect substellar companions because it improves contrasts in direct imaging. Characterising this emission from accreting exoplanets allows for the testing of planet formation theories. Aims. We characterise the young circumbinary planetary mass companion 2MASS J01033563-5515561 (AB)b (Delorme 1 (AB)b) through medium-resolution spectroscopy. Methods. We used the new narrow-field mode for the MUSE integral-field spectrograph, located on the ESO Very Large Telescope, during science verification time to obtain optical spectra of Delorme 1 (AB)b. Results. We report the discovery of very strong Hα and Hβ emission, accompanied by He I emission. This is consistent with an active accretion scenario. We provide accretion rate estimates obtained from several independent methods and find a likely mass of 12−15 MJup for Delorme 1 (AB)b. This is also consistent with previous estimates. Conclusions. Signs of active accretion in the Delorme 1 system might indicate a younger age than the ∼30−40 Myr expected from a likely membership in Tucana-Horologium (THA). Previous works have also shown the central binary to be overluminous, which gives further indication of a younger age. However, recent discoveries of active discs in relatively old (∼40 Myr), very low-mass systems suggests that ongoing accretion in Delorme 1 (AB)b might not require in and of itself that the system is younger than the age implied by its THA membership.

scholarly journals Medium-resolution spectrum of the exoplanet HIP 65426 b

2021 ◽  
Vol 648 ◽  
pp. A59
Author(s):  
S. Petrus ◽  
M. Bonnefoy ◽  
G. Chauvin ◽  
B. Charnay ◽  
G.-D. Marleau ◽  
...  
Keyword(s):  
Radial Velocity ◽  
Adaptive Optics ◽  
Molecular Mapping ◽  
Gravitational Instability ◽  
Atmospheric Models ◽  
Star Forming ◽  
Star Forming Regions ◽  
Medium Resolution ◽  
Core Accretion ◽  
Integral Field

Medium-resolution integral-field spectrographs (IFS) coupled with adaptive-optics such as Keck/OSIRIS, VLT/MUSE, or SINFONI are appearing as a new avenue for enhancing the detection and characterization capabilities of young, gas giant exoplanets at large heliocentric distances (>5 au). We analyzed K-band VLT/SINFONI medium-resolution (Rλ ~5577) observations of the young giant exoplanet HIP 65426 b. Our dedicated IFS data analysis toolkit (TExTRIS) optimized the cube building, star registration, and allowed for the extraction of the planet spectrum. A Bayesian inference with the nested sampling algorithm coupled with the self-consistent forward atmospheric models BT-SETTL15 and Exo-REM using the ForMoSA tool yields Teff = 1560 ± 100 K, log(g) ≤ 4.40 dex, [M/H] = 0.05−0.22+0.24 dex, and an upper limit on the C/O (≤0.55). The object is also re-detected with the so-called “molecular mapping” technique. The technique yields consistent atmospheric parameters, but the loss of the planet pseudo-continuum in the process degrades or modifies the constraints on these parameters. The solar to sub-solar C/O ratio suggests an enrichment by solids at formation if the planet was formed beyond the water snowline (≥20 au) by core accretion (CA hereafter). However, a formation by gravitational instability (GI hereafter) cannot be ruled out. The metallicity is compatible with the bulk enrichment of massive Jovian planets from the Bern planet population models. Finally, we measure a radial velocity of 26 ± 15 km s−1 compatible with our revised measurement on the star. This is the fourth imaged exoplanet for which a radial velocity can be evaluated, illustrating the potential of such observations for assessing the coevolution of imaged systems belonging to star forming regions, such as HIP 65426.

Adaptive optics systems for HARMONI: a visible and near-infrared integral field spectrograph for the E-ELT

2010 ◽  
Author(s):  
Thierry Fusco ◽  
Niranjan Thatte ◽  
Serge Meimon ◽  
Matthias Tecza ◽  
Fraser Clarke ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
Near Infrared ◽  
Integral Field Spectrograph ◽  
Integral Field

scholarly journals Evidence for an accreting massive black hole in He 2–10 from adaptive optics integral field spectroscopy

2020 ◽  
Vol 494 (2) ◽  
pp. 2004-2011 ◽  
Author(s):  
Rogemar A Riffel
Keyword(s):  
Black Hole ◽  
Adaptive Optics ◽  
Near Infrared ◽  
Dwarf Galaxy ◽  
Line Emission ◽  
Massive Black Hole ◽  
Star Forming ◽  
Star Forming Regions ◽  
Integral Field Spectrograph ◽  
Integral Field

ABSTRACT Henize 2–10 is a blue dwarf galaxy with intense star formation and one the most intriguing question about it is whether or not it hosts an accreting massive black hole. We use H and K-band integral field spectra of the inner 130 pc × 130 pc of He 2–10 to investigate the emission and kinematics of the gas at unprecedented spatial resolution. The observations were done using the Gemini Near-Infrared Integral Field Spectrograph (NIFS) operating with the ALTAIR adaptive optics module and the resulting spatial resolutions are 6.5 and 8.6 pc in the K and H bands, respectively. Most of the line emission is due to excitation of the gas by photoionization and shocks produced by the star forming regions. In addition, our data provide evidence of emission of gas excited by an active galactic nucleus located at the position of the radio and X-ray sources, as revealed by the analysis of the emission-line ratios. The emission lines from the ionized gas in the field present two kinematic components: one narrow with a velocity field suggesting a disc rotation and a broad component due to winds from the star forming regions. The molecular gas shows only the narrow component. The stellar velocity dispersion map presents an enhancement of about 7 km s−1 at the position of the black hole, consistent with a mass of $1.5^{+1.3}_{-1.3}\times 10^6$ M⊙.

scholarly journals Science with EPICS, the E-ELT planet finder

2010 ◽  
Vol 6 (S276) ◽  
pp. 343-348
Author(s):  
Raffaele Gratton ◽  
Markus Kasper ◽  
Christophe Vérinaud ◽  
Mariangela Bonavita ◽  
Hans M. Schmid
Keyword(s):  
Adaptive Optics ◽  
Near Infrared ◽  
Large Telescope ◽  
High Performing ◽  
System A ◽  
Reflected Light ◽  
Integral Field Spectrograph ◽  
Adaptive Optics System ◽  
Integral Field

AbstractEPICS is the proposed planet finder for the European Extremely Large Telescope. EPICS is a high contrast imager based on a high performing extreme adaptive optics system, a diffraction suppression module, and two scientific instruments: an Integral Field Spectrograph (IFS) for the near infrared (0.95-1.65 μm), and a differential polarization imager (E-POL). Both these instruments should allow imaging and characterization of planets shining in reflected light, possibly down to Earth-size. A few high interesting science cases are presented.

scholarly journals Spatially Resolved Spectroscopy to Confirm or Disprove Dual Active Galactic Nuclei

2013 ◽  
Vol 9 (S304) ◽  
pp. 371-374
Author(s):  
Rosalie C. McGurk ◽  
Claire E. Max ◽  
Anne Medling ◽  
Gregory A. Shields
Keyword(s):  
Emission Line ◽  
Active Galactic Nuclei ◽  
Adaptive Optics ◽  
Near Infrared ◽  
Galactic Nuclei ◽  
Spatially Resolved ◽  
Spatially Resolved Spectroscopy ◽  
Integral Field Spectrograph ◽  
Guide Star ◽  
Integral Field

AbstractWhen galaxies merge, gas accretes onto both central supermassive black holes. Thus, one expects to see dual active galactic nuclei (AGNs) in a fraction of galaxy mergers. Candidates for galaxies containing dual AGNs have been identified by the presence of double-peaked narrow [O III] emission lines and by high spatial resolution images of close galaxy pairs. 30% of double-peaked narrow [OIII] emission line SDSS AGNs have two spatial components within a 3″ radius. However, spatially resolved spectroscopy is needed to confirm these galaxy pairs as systems with double AGNs. With the Keck 2 Laser Guide Star Adaptive Optics system and the OSIRIS near-infrared integral field spectrograph, we obtained spatially resolved spectra for SDSS J095207.62+255257.2, confirming that it contains a Type 1 and a Type 2 AGN separated by 4.8 kpc (=1.0″). We performed similar integral field and long-slit spectroscopy observations of more spatially separated candidate dual AGNs and will report on the varied results. By assessing what fraction of radio-quiet double-peaked emission line SDSS AGNs are true dual AGNs, we can better constrain the statistics of dual AGNs and characterize physical conditions throughout these interacting AGNs.

scholarly journals Direct imaging and spectroscopy of exoplanets with the ELT/HARMONI high-contrast module

2021 ◽  
Author(s):  
Mathis Houllé ◽  
Arthur Vigan ◽  
Alexis Carlotti ◽  
Élodie Choquet ◽  
Faustine Cantalloube ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
Near Infrared ◽  
Direct Detection ◽  
Imaging Techniques ◽  
High Contrast ◽  
Contrast Imaging ◽  
High Contrast Imaging ◽  
Medium Resolution ◽  
Imaging And Spectroscopy ◽  
Integral Field Spectrograph

<p>Combining high-contrast imaging with medium-resolution spectroscopy has recently been shown to significantly boost the direct detection of exoplanets. In this optic, HARMONI, one of the first-light instruments to be mounted on ESO's ELT, will be equipped with a single-conjugated adaptive optics system to reach the diffraction limit of the ELT in H and K bands, a high-contrast module dedicated to exoplanet imaging, and a medium-resolution (up to R = 17 000) optical and near-infrared integral field spectrograph. When combined, these systems will provide unprecedented contrast limits at separations between 50 and 400 mas. We will present in this talk the results of extensive simulations of exoplanet observations with the HARMONI high-contrast module. We used an end-to-end model of the instrument to simulate observations based on realistic observing scenarios and conditions. We then analyzed these observations with the so-called "molecule mapping" technique, which has shown in recent studies its efficiency to disentangle planetary companions from their host star and boost their signal. Although HARMONI has not been fully designed for high-contrast imaging, we will show that it should greatly outperform the current dedicated instruments, such as SPHERE on the VLT. We detect planets above 5σ in 2 hours at contrasts up to 16 mag and separations down to 75 mas in several spectral configurations of the instrument. Simulating planets from population synthesis models, we could image in this amount of time companions as close as 1 AU from a host star at 30 pc and as light as 2 M<sub>Jup</sub>. We show that taking advantage of the combination of high-contrast imaging and medium-resolution spectroscopy through molecule mapping allows us to access much fainter planets (up to 2.5 mag) than the standard high-contrast imaging techniques. We also demonstrate that HARMONI should be available for near-critical exoplanet observations with this method during 60 to 70% of telescope time at the ELT.</p>

Deep Near-Infrared Surveys and Young Brown Dwarf Populations in Star-Forming Regions

2003 ◽  
Vol 211 ◽  
pp. 87-90
Author(s):  
M. Tamura ◽  
T. Naoi ◽  
Y. Oasa ◽  
Y. Nakajima ◽  
C. Nagashima ◽  
...  
Keyword(s):  
High Resolution ◽  
Adaptive Optics ◽  
Near Infrared ◽  
Brown Dwarf ◽  
Ir Camera ◽  
Star Forming ◽  
Star Forming Regions ◽  
New Instrument ◽  
Infrared Surveys ◽  
Low Mass

We are currently conducting three kinds of IR surveys of star forming regions (SFRs) in order to seek for very low-mass young stellar populations. First is a deep JHKs-bands (simultaneous) survey with the SIRIUS camera on the IRSF 1.4m or the UH 2.2m telescopes. Second is a very deep JHKs survey with the CISCO IR camera on the Subaru 8.2m telescope. Third is a high resolution companion search around nearby YSOs with the CIAO adaptive optics coronagraph IR camera on the Subaru. In this contribution, we describe our SIRIUS camera and present preliminary results of the ongoing surveys with this new instrument.

scholarly journals Near-Infrared Spectroscopy of the Surface of Mars Derived from TIGER Spectro-Imaging Data

1995 ◽  
Vol 149 ◽  
pp. 298-299
Author(s):  
P. Martin ◽  
P.C. Pinet ◽  
R. Bacon ◽  
A. Rousset
Keyword(s):  
Infrared Spectroscopy ◽  
Spatial Resolution ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Western Hemisphere ◽  
Imaging Data ◽  
Integral Field Spectrograph ◽  
Integral Field ◽  
Spectro Imaging

AbstractHigh spectral and spatial resolution telescopic observations of the western hemisphere of Mars, using the integral field spectrograph TIGER at 0.8-1.1 µm, are described.

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