scholarly journals The GROUnd-based Secondary Eclipse project - GROUSE

2010 ◽  
Vol 6 (S276) ◽  
pp. 487-488
Author(s):  
Ernst de Mooij ◽  
Remco de Kok ◽  
Bas Nefs ◽  
Matteo Brogi ◽  
Ignas Snellen
Keyword(s):  
Energy Distribution ◽  
Wavelength Range ◽  
Near Infrared ◽  
Spectral Energy Distribution ◽  
Energy Budgets ◽  
Spectral Energy ◽  
Hot Jupiters ◽  
Eclipse Observations ◽  
Infrared Wavelengths ◽  
Optical Wavelengths

AbstractSecondary eclipse observations of exoplanets at near-infrared wavelengths are important to constrain the energy budgets of hot-Jupiters, since they probe the radiation from the planet's atmosphere at the peak of the spectral energy distribution. Since this wavelength range is accesible from the ground, we have started the GROUnd-based Secondary Eclipse (GROUSE) project. As part of the GROUSE project, we target a sample of hot-Jupiters at near-infrared and optical wavelengths. Planets include TrES-3b, HAT-P-1, WASP-18b and WASP-33b.

scholarly journals Revised SED of the triple protostellar system VLA 1623−2417

2018 ◽  
Vol 615 ◽  
pp. L14 ◽  
Author(s):  
N. M. Murillo ◽  
D. Harsono ◽  
M. McClure ◽  
S.-P. Lai ◽  
M. R. Hogerheijde
Keyword(s):  
Energy Distribution ◽  
Near Infrared ◽  
Spectral Energy Distribution ◽  
Spectral Energy ◽  
Gas Emission ◽  
Circumstellar Gas ◽  
Infrared Wavelengths ◽  
Previous Assumption

Context. VLA 1623−2417 is a triple protostellar system deeply embedded in Ophiuchus A. Sources A and B have a separation of 1.1″, making their study difficult beyond the submillimeter regime. Lack of circumstellar gas emission suggested that VLA 1623−2417 B has a very cold envelope and is much younger than source A, which is generally considered the prototypical Class 0 source. Aims. We explore the consequences of new ALMA Band 9 data on the spectral energy distribution (SED) of VLA 1623−2417 and their inferred nature. Methods. We constructed and analyzed the SED of each component in VLA 1623−2417 using dust continuum observations spanning from centimeter to near-infrared wavelengths. Results. The ALMA Band 9 data presented in this work show that the SED of VLA 1623−2417 B does not peak at 850 µm as previously expected, but instead presents the same shape as VLA 1623−2417 A at wavelengths shorter than 450 µm. Conclusions. The results presented in this work indicate that the previous assumption that the flux in Herschel and Spitzer observations is solely dominated by VLA 1623−2417 A is not valid, and instead, VLA 1623−2417 B most likely contributes a significant portion of the flux at λ < 450 µm. These results, however, do not explain the lack of circumstellar gas emission and puzzling nature of VLA 1623−2417 B.

scholarly journals Exploring the dimming event of RW Aurigae A through multi-epoch VLT/X-shooter spectroscopy

2019 ◽  
Vol 625 ◽  
pp. A49 ◽  
Author(s):  
M. Koutoulaki ◽  
S. Facchini ◽  
C. F. Manara ◽  
A. Natta ◽  
R. Garcia Lopez ◽  
...  
Keyword(s):  
Energy Distribution ◽  
Physical Properties ◽  
Near Infrared ◽  
Accretion Rate ◽  
Spectral Energy Distribution ◽  
Spectral Energy ◽  
Infrared Excess ◽  
Mass Accretion Rate ◽  
Near Ir ◽  
T Tauri

Context. RW Aur A is a classical T Tauri star that has suddenly undergone three major dimming events since 2010. The reason for these dimming events is still not clear. Aims. We aim to understand the dimming properties, examine accretion variability, and derive the physical properties of the inner disc traced by the CO ro-vibrational emission at near-infrared wavelengths (2.3 μm). Methods. We compared two epochs of X-shooter observations, during and after the dimming. We modelled the rarely detected CO bandhead emission in both epochs to examine whether the inner disc properties had changed. The spectral energy distribution was used to derive the extinction properties of the dimmed spectrum and compare the infrared excess between the two epochs. Lines tracing accretion were used to derive the mass accretion rate in both states. Results. The CO originates from a region with physical properties of T = 3000 K, NCO = 1 × 1021 cm−2 and vk sin i = 113 km s−1. The extinction properties of the dimming layer were derived with the effective optical depth ranging from τeff ~2.5−1.5 from the UV to the near-IR. The inferred mass accretion rate Ṁacc is ~1.5 × 10−8 M⊙ yr−1 and ~2 × 10−8 M⊙ yr−1 after and during the dimming respectively. By fitting the spectral energy distribution, additional emission is observed in the infrared during the dimming event from dust grains with temperatures of 500–700 K. Conclusions. The physical conditions traced by the CO are similar for both epochs, indicating that the inner gaseous disc properties do not change during the dimming events. The extinction curve is flatter than that of the interstellar medium, and large grains of a few hundred microns are thus required. When we correct for the observed extinction, the mass accretion rate is constant in the two epochs, suggesting that the accretion is stable and therefore does not cause the dimming. The additional hot emission in the near-IR is located at about 0.5 au from the star and is not consistent with an occulting body located in the outer regions of the disc. The dimming events could be due to a dust-laden wind, a severe puffing-up of the inner rim, or a perturbation caused by the recent star-disc encounter.

scholarly journals A Deep JI Survey of the Pleiades for Freely-Floating Superplanets and Brown Dwarfs at the Deuterium Burning Limit

2003 ◽  
Vol 211 ◽  
pp. 185-186
Author(s):  
M. J. Schwartz ◽  
E. E. Becklin ◽  
B. Zuckerman
Keyword(s):  
Energy Distribution ◽  
Proper Motion ◽  
Near Infrared ◽  
Profile Analysis ◽  
Spectral Energy Distribution ◽  
Brown Dwarfs ◽  
Spectral Energy ◽  
Preliminary Results ◽  
Methane Absorption ◽  
Lower Limits

We present preliminary results from a deep near-infrared J-band and I-band photometric survey of the Pleiades for freely-floating superplanets and brown dwarfs (BD) near the deuterium burning limit (DBL). With limiting magnitudes of J=20.5 and I=23.5, we have selected candidate Pleiads on the basis of evolutionary tracks, color-magnitudes, and I-J color lower limits (non-detections at deep I-band). Likelihoods of membership will be ultimately determined by a combination of image profile analysis, spectral energy distribution, proper motion, and low-resolution measurements of near-infrared water and/or methane absorption slopes. If confirmed, our faintest candidates are predicted to have made the transition from L to T spectral types with temperatures down to 820 K, and masses approaching 10 MJup.

scholarly journals Nature of the Dusty S-cluster Object (DSO/G2): Pre-main-sequence star with non-spherical dusty envelope

2016 ◽  
Vol 11 (S322) ◽  
pp. 231-232
Author(s):  
M. Zajaček ◽  
M. Valencia-S. ◽  
B. Shahzamanian ◽  
F. Peissker ◽  
A. Eckart ◽  
...  
Keyword(s):  
Energy Distribution ◽  
Main Sequence ◽  
Near Infrared ◽  
Spectral Energy Distribution ◽  
Main Sequence Star ◽  
Continuum Emission ◽  
Spectral Energy ◽  
Galactic Centre ◽  
Infrared Excess ◽  
Sgr A

AbstractNear-infrared observations reveal several infrared-excess sources near the Galactic Centre with emission lines present in their spectra. One of these objects, DSO/G2, which moves around the supermassive black hole (Sgr A*) on a highly eccentric orbit, passed the pericentre at approximately 160 AU in 2014. It remained compact, which implies that at least in this case it is a star embedded in a dusty envelope. The spectral energy distribution and the detection of polarized continuum emission indicate that it is probably a pre-main-sequence star surrounded by a dense envelope with bipolar cavities. In addition, the star associated with DSO/G2 plausibly develops a bow shock due to its supersonic motion. The model of the star surrounded by the non-spherical dusty envelope can reproduce the main characteristics of the DSO/G2 source: 1. spectral energy distribution in near-infrared bands; 2. linear polarization in Ks band; and 3. the overall compact behaviour.

scholarly journals Simultaneous Spectral Energy Distribution and Near-infrared Interferometry Modeling of HD 142666

2018 ◽  
Vol 866 (1) ◽  
pp. 23 ◽  
Author(s):  
Claire L. Davies ◽  
Stefan Kraus ◽  
Tim J. Harries ◽  
Alexander Kreplin ◽  
John D. Monnier ◽  
...  
Keyword(s):  
Energy Distribution ◽  
Near Infrared ◽  
Spectral Energy Distribution ◽  
Spectral Energy ◽  
Infrared Interferometry

scholarly journals A quasar–galaxy mixing diagram: quasar spectral energy distribution shapes in the optical to near-infrared

2013 ◽  
Vol 434 (4) ◽  
pp. 3104-3121 ◽  
Author(s):  
Heng Hao ◽  
Martin Elvis ◽  
Angela Bongiorno ◽  
Gianni Zamorani ◽  
Andrea Merloni ◽  
...  
Keyword(s):  
Energy Distribution ◽  
Near Infrared ◽  
Spectral Energy Distribution ◽  
Spectral Energy

scholarly journals Spectral Energy Distribution of Be Stars

1987 ◽  
Vol 92 ◽  
pp. 206-207
Author(s):  
Dieter Kaiser ◽  
Reinhard W. Hanuschik
Keyword(s):  
Energy Distribution ◽  
Wavelength Range ◽  
Spectral Resolution ◽  
Spectral Energy Distribution ◽  
Spectral Energy ◽  
Be Stars ◽  
Spectral Energy Distributions ◽  
Energy Distributions ◽  
The University

During two observation periods in Nov./Dec. 1981 and April/ May 1985, absolute spectral energy distributions of 41 southern and equatorial Be stars were photometrically measured at 10 Å spectral resolution in the wavelength range between 3200 Å and 8500 Å, using the scanning spectrophotometer attached to the 61 cm telescope of the University of Bochum at La Silla/Chile. Spectral fluxes of the program stars have been determined with an error of 0m.03 or less.

scholarly journals AGILE, Fermi, Swift, and GASP/WEBT multi-wavelength observations of the high-redshift blazar 4C +71.07 in outburst

2019 ◽  
Vol 621 ◽  
pp. A82 ◽  
Author(s):  
S. Vercellone ◽  
P. Romano ◽  
G. Piano ◽  
V. Vittorini ◽  
I. Donnarumma ◽  
...  
Keyword(s):  
Energy Distribution ◽  
Near Infrared ◽  
High Redshift ◽  
Spectral Energy Distribution ◽  
Optical Emission ◽  
High Mass ◽  
Spectral Energy ◽  
Emission Region ◽  
Energy Bands ◽  
Spectrum Radio

Context. The flat-spectrum radio quasar 4C +71.07 is a high-redshift (z = 2.172), γ-loud blazar whose optical emission is dominated by thermal radiation from the accretion disc. Aims. 4C +71.07 has been detected in outburst twice by the AGILE γ-ray satellite during the period from the end of October to mid-November 2015, when it reached a γ-ray flux of the order of F(E >  100 MeV)=(1.2 ± 0.3)×10−6 photons cm−2 s−1 and F(E > 100 MeV)=(3.1 ± 0.6)×10−6 photons cm−2 s−1, respectively, allowing us to investigate the properties of the jet and the emission region. Methods. We investigated its spectral energy distribution by means of almost-simultaneous observations covering the cm, mm, near-infrared, optical, ultraviolet, X-ray, and γ-ray energy bands obtained by the GASP-WEBT Consortium and the Swift, AGILE, and Fermi satellites. Results. The spectral energy distribution of the second γ-ray flare (whose energy coverage is more dense) can be modelled by means of a one-zone leptonic model, yielding a total jet power of about 4 × 1047 erg s−1. Conclusions. During the most prominent γ-ray flaring period our model is consistent with a dissipation region within the broad-line region. Moreover, this class of high-redshift, flat-spectrum radio quasars with high-mass black holes might be good targets for future γ-ray satellites such as e-ASTROGAM.

scholarly journals The near-infrared spectral energy distribution ofβPictoris b

2013 ◽  
Vol 555 ◽  
pp. A107 ◽  
Author(s):  
M. Bonnefoy ◽  
A. Boccaletti ◽  
A.-M. Lagrange ◽  
F. Allard ◽  
C. Mordasini ◽  
...  
Keyword(s):  
Energy Distribution ◽  
Near Infrared ◽  
Spectral Energy Distribution ◽  
Spectral Energy ◽  
Infrared Spectral
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