SH2-101 (Tulip Nebula) and jet nebula from black hole Cyg X-1
SH2-101 (also known as Tulip Nebula) is an emission nebula in constellation Cygnus. It is assumed that the nebula is ionized by the Cygnus OB3 association, which extends within a distance of about 5000 to 8000 light-years from Earth, see [1]. One famous member of this association is HDE 226868, which forms a binary system with the suspected black hole Cygnus X-1. The black hole emits jets that interact with the surrounding matter. The nebula ionized in this way can be seen in the images below.
Click on the image to load a full resolution version using a JavaScript viewer.
According to [2], the blue structure on the right boundary is caused by a jet interacting with the interstellar medium.
The jet is ejected from the black hole Cygnus X-1, which forms a binary system with HDE 226868 (marked by a small cross in the JavaScript viewer when clicked on the image).
The black hole accretes matter from its companion, and some of the gas that does not fall into the black hole is shot out in form of these jets.
Compared to SH2-101, the jet nebula is bright in OIII and SII light and therefore appears deep blue with some red in the image.
A pseudo-color image showing SH2-101 (Tulip Nebula) and the jet nebula from black hole Cyg X-1 in H-alpha light. The image is colored according to the real brightness (without dynamic range compression) as per the legend.
Each tic in the legend corresponds to one magnitude step or a brightness factor of 100.4≈2.5, respectively.
Image data
| FOV: | 0.75° × 0.51° | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Date: | 2019-2022 | ||||||||||
| Location: | Pulsnitz, Germany | ||||||||||
| Instrument: | 400mm Newton at f=1520mm | ||||||||||
| Camera Sensor: | Panasonic MN34230 | ||||||||||
| Orientation: | North is up (exactly) | ||||||||||
| Scale: | 0.8 arcsec/pixel (at full resolution) | ||||||||||
| Total exposure times: |
|
Image processing
All image processing steps are deterministic. There was no manual retouching or any other kind of non-reproducible adjustment. No AI was used; the images shown here are the results of deterministic calculations and not hallucinations of an AI.The software which was used can be downloaded here.
Image processing steps were:
- Bias and dark current subtraction, flatfield correction, noise estimation
- Alignment and brightness calibration using stars
- Stacking with masking unlikely values and background correction
- Extracting stars from the emission line images using information from continuum images
- Denoising and deconvolution both components (stars and residual)
- RGB-composition
- Dynamic range compression using non-linear high-pass filter
- Tonal curve correction
References
- Anjali Rao, Poshak Gandhi, Christian Knigge, John A Paice, Nathan W C Leigh, Douglas Boubert. (2020). "Kinematic study of the association Cyg OB3 with Gaia DR2". Monthly Notices of the Royal Astronomical Society. 495 (1): 1491–1500, Astronomy & Astrophysics 630: A137.
- D. M. Russell, R. P. Fender, E. Gallo, C. R. Kaiser. (2007). "The jet-powered optical nebula of Cygnus X–1". Monthly Notices of the Royal Astronomical Society. 376 (3): 1341–1349
