Please find the whole list of my publications on ADS, e.g. searching for Errmann, Ronny on

Alternativly, my ORCID can be used: 0000-0002-3683-1952 ( – Ronny Errmann).

A selection of Publications:

HiFLEx—A Highly Flexible Package to Reduce Cross-dispersed Echelle Spectra

Errmann, Ronny; Cook, Neil; Anglada-Escudé, Guillem; Sithajan, Sirinrat; Mkrtichian, David; Semenko, Eugene; Martin, William; Tanvir, Tabassum S.; Feng, Fabo; Collett, James L.; Jones, Hugh R. A.

We describe a flexible data reduction package for high resolution cross-dispersed echelle data. This open-source package is developed in Python and includes optional GUIs for most of the steps. It does not require any pre-knowledge about the form or position of the echelle-orders. It has been tested on cross-dispersed echelle spectrographs between 13k and 115k resolution (bifurcated fiber-fed spectrogaph ESO-HARPS and single fiber-fed spectrograph TNT-MRES). HiFLEx can be used to determine radial velocities and is designed to use the TERRA package but can also control the radial velocity packages such as CERES and SERVAL to perform the radial velocity analysis. Tests on HARPS data indicates radial velocities results within ±3 m s-1 of the literature pipelines without any fine tuning of extraction parameters.

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6- and 8-telescope discrete beam combiners

Errmann, Ronny; Minardi, Stefano

We conduct an extensive numerical study to single out the best performing rectangular array of evanescently coupled waveguides (discrete beam combiner) that can be used as an integrated optic beam combiner for 6-telescopes at once. We found that the performance of a discrete beam combiner only depends on the conditioning of the Visibility to Pixel Matrix (V2PM) describing it. However, we found that the condition number of V2PM pertaining to different beam combiner architectures cannot be compared. We further report on the possible input waveguide configuration of an 8-telescope discrete beam combiner featuring 8×8 or 9×9 waveguides.

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Interferometric nulling of four channels with integrated optics

Errmann, Ronny; Minardi, Stefano; Labadie, Lucas; Muthusubramanian, Balaji; Dreisow, Felix; Nolte, Stefan; Pertsch, Thomas

Nulling interferometry has been identified as a competitive technique for the detection of extrasolar planets. In its basic form, the technique consists of combining out-of-phase a single pair of telescopes to effectively null the light of a bright star and reveal the dim glow of the companion. However, in order to mitigate the effect of the stellar leaks through the interferometer, a broad angular central null is required. The hierarchical combination of several pairs of telescopes can accomplish this task. We have manufactured and tested with monochromatic light an integrated optics component, which combines a linear array of four telescopes in the nulling mode envisaged by Angel and Woolf [Astroph. J. 475, 373–379 (1997). By simulating in the laboratory the motion of a star in the sky, we could measure the expected angular transmission of the four-telescope nuller. Moreover, the tests have demonstrated a broad nulling scaling as the fourth power of the baseline delay.

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