FACT Publications

2024:

[98] A. Gokus et al. (others, FACT) Rapid variability of Markarian 421 during extreme flaring as seen through the eyes of XMM–Newton,
MNRAS 529,2 1450-1462; https://doi.org/10.1093/mnras/stae643

2023:

[97] A. Gokus et al. (others, FACT) Revealing rapid short-time variability of Mrk 421 with XMM-Newton,
Bulletin of the American Astronomical Society, Vol. 55, No. 4; https://baas.aas.org/pub/2023n4i100p56

[96] F. Schuessler at al. (others, FACT) Joint searches by FACT, H.E.S.S., MAGIC and VERITAS for VHE gamma-ray emission associated with neutrinos detected by IceCube,
proceedings of the 38th ICRC; https://arxiv.org/abs/2309.15469

[T2] F. Rehbein et al. (based on FACT) CALIBRATION OF 122 SENSL MICROFJ-60035 SIPMS AND THE REDUCTION OF OPTICAL CROSS-TALK DUE TO COUPLED LIGHT GUIDES,
Revista Mexicana de Astronomia y Astrofisica, 59, 379–388 (2023); https://doi.org/10.22201/ia.01851101p.2023.59.02.14

2022:

[95] A.G. Markowitz et al. (FACT, others) Rapid X-ray variability in Mkn 421 during a multiwavelength campaign,
MNRAS 513,2 (2022) 1662–1679; https://doi.org/10.1093/mnras/stac917

2021:

[94] A. Arbet-Engels et al. (FACT Collaboration) Long-term multi-band photometric monitoring of Mrk 501,
A&A, 655 (2021) A93, https://doi.org/10.1051/0004-6361/202141886

[93] A. Arbet-Engels et al. (FACT Collaboration) The relentless variability of Mrk 421 from the TeV to the radio,
A&A, 647 (2021) A88, https://doi.org/10.1051/0004-6361/201935557

[92] V.A. Acciari et al. (MAGIC, FACT, others) Investigation of the correlation patterns and the Compton dominance variability of Mrk 421 in 2017,
A&A, 655 (2021) A89, https://doi.org/10.1051/0004-6361/202141004

37th ICRC (Berlin (online), 2021)

[91] D. Dorner et al., FACT - Highlights from more than Eight Years of Unbiased TeV Monitoring ,
PoS(ICRC2021) 851

[90] B. Schleicher et al., FACT - database-based Analysis and Spectrum Calculations ,
PoS(ICRC2021) 760

[89] V. Sliusar et al., Relentless multi-wavelength variability of Markarian 421 and Markarian 501
PoS(ICRC2021) 808

[88] R. Iotov et al., Periodicity Analysis of Mrk 501 and Mrk 421 in Gamma Rays
PoS(ICRC2021) 879

[87] S.M. Wagner et al., Statistical properties of flux variations in blazar light curves at GeV and TeV energies
PoS(ICRC2021) 868

[86] A. Gokus et al., Multi-wavelength study of Mrk 421 during a TeV flare
PoS(ICRC2021) 869

[85] A. Arbet-Engels et al., Unveiling the complex correlation patterns in Mrk 421
PoS(ICRC2021) 834

[84] A. Arbet-Engels et al., Extreme Blazars under the eyes of MAGIC
PoS(ICRC2021) 865

[83] V.A. Acciari et al., Multiwavelength variability and correlation studies of Mrk421 during historically low X-ray and gamma-ray activity in 2015 - 2016
PoS(ICRC2021) 866

[82] S. Sakurai et al., Studying the long-term spectral and temporal evolution of 1ES 1959+650
PoS(ICRC2021) 858

[81] K. Satalecka et al., Searching for VHE gamma-ray emission associated with IceCube neutrino alerts using FACT, H.E.S.S., MAGIC, and VERITAS
PoS(ICRC2021) 960

In: proceedings of the 37th ICRC, Berlin, 2021 http://pos.sissa.it/395

2020:

[80] V. A. Acciari et al. (MAGIC, FACT, others) An intermittent extreme BL Lac: MWL study of 1ES 2344+514 in an enhanced state,
MNRAS 498, 3 (2020), https://doi.org/10.1093/mnras/staa1702

[79] V. A. Acciari et al. (MAGIC, FACT, others) Study of the variable broadband emission of Markarian 501 during the most extreme Swift X-ray activity,
A&A 637, A86 (2020), https://doi.org/10.1051/0004-6361/201834603

2019:

[78] V.Sliusar et al. (FACT Collaboration) 5.5 years multi-wavelength variability of Mrk 421: evidences of leptonic emission from the radio to TeV,
Proceedings of HEPRO VII, Barcelona (2019) , https://arxiv.org/abs/1909.13106

[77] D. Dorner et al. (FACT Collaboration) Flux States of Active Galactic Nuclei,
Galaxies 2019, 7(2), 57; https://doi.org/10.3390/galaxies7020057

[76] M.M. Gonzalez et al. (FACT, HAWC, M@TE), Unbiased Long-Term Monitoring at TeV Energies,
Galaxies 2019, 7(2), 51; https://doi.org/10.3390/galaxies7020051

[75] B. Schleicher et al. (FACT Collaboration), Fractional Variability—A Tool to Study Blazar Variability,
Galaxies 2019, 7(2), 62; https://doi.org/10.3390/galaxies7020062

ATEL
[A12] #13165: FACT: 1ES 2344+51.4 in High State at TeV Energies
[A11] #12891: FACT: Upper limit on TeV emission from Fermi J0139.5+2928 measured with FACT
[A10] #12680: FACT: Continued High Activity of Mrk 421 at TeV Energies

36th ICRC (Madison, 2019)

[74] D. Dorner et al., FACT - Highlights from more than Seven Years of Unbiased Monitoring at TeV Energies,
PoS(ICRC2019) 665

[73] V. Sliusar et al., FACT - Multi-wavelength analysis of more than 30 flares of Mrk 421,
PoS(ICRC2019) 796

[72] M. Beck et al., FACT - Probing the Periodicity of Mrk 421 and Mrk 501,
PoS(ICRC2019) 630

[71] A. Arbet-Engels et al., (FACT, MAGIC) Studying the Extreme Behaviour of 1ES 2344+51.4,
PoS(ICRC2019) 620

In: proceedings of the 36th ICRC, Madison, 2019 http://pos.sissa.it/cgi-bin/reader/conf.cgi?confid=358

2018:

[T1] T. Bretz, Zenith angle dependence of the cosmic ray rate as measured with imaging air-Cherenkov telescopes,
Astropart. Phys., 111, 72-86 (2018)

[70] C.Romoli et al. (FACT, H.E.S.S.), Flux Distribution of Gamma-Ray Emission in Blazars: The Example of Mrk 501,
Galaxies 2018, 6(4), 135; https://doi.org/10.3390/galaxies6040135

[69] MAGIC Collaboration, Ahnen et al. (MAGIC,FACT,VERITAS,others) The extreme HBL behaviour of Mrk 501 during 2012,
A&A 620 (2018) A181, doi:10.1051/0004-6361/201833704

ATEL
[A9] #11184: FACT: Exceptional Flare of Mrk 421 at TeV energies

2017:

[68] F.Temme et al. Long-Term Monitoring of Bright Blazars in the Multi-GeV to TeV Range with FACT,
Galaxies 2017, 5(1), 18; doi:10.3390/galaxies5010018

[67] J. Adam et al. Mirror position determination for the alignment of Cherenkov Telescopes,
NIM A, Vol. 860; p. 1-5, doi:10.1016/j.nima.2017.03.062

[66] N. Neise et al. FACT – Status and experience from five years of operation of the first G-APD Cherenkov Telescope,
NIM A, Vol. 876; p. 17-20, doi:10.1016/j.nima.2016.12.053

ATEL
[A8] #11086: FACT: Mrk 421 exceptionally bright at TeV energies
[A7] #11077: FACT, HAWC: Mrk 421 showing enhanced activity at TeV energies with two short bright outbursts

35th ICRC (Busan, 2017)

[65] M. Mahlke et al., FACT - Searching for periodicity in five-year light-curves of Active Galactic Nuclei,
PoS(ICRC2017) 612

[64] D. Dorner et al., FACT - Highlights from more than Five Years of Unbiased Monitoring at TeV Energies,
PoS(ICRC2017) 609

[63] D. Dorner et al., FACT - Time-Resolved Blazar SEDs,
PoS(ICRC2017) 608

[62] M. Noethe et al., FACT - Performance of the first Cherenkov Telescope operating with SiPMs,
PoS(ICRC2017) 791

[61] S.A. Mueller et al., Single Photon Extracion for FACT's SiPMs allows for Novel IACT Event Representation,
PoS(ICRC2017) 801

[60] M. Noethe et al., Measuring the Optical Point Spread Function of FACT Using the Cherenkov Camera,
PoS(ICRC2017) 790

[59] D. Hildebrand et al., Using Charged Cosmic Ray Particles to Monitor the Data Quality of FACT,
PoS(ICRC2017) 779

[58] D. Hildebrand et al., Higher Order Temperature Dependence of SiPM used in FACT,
PoS(ICRC2017) 778

[57] M. Santander et al. (IceCube, FACT, MAGIC, H.E.S.S., VERITAS), Searching for VHE gamma-ray emission associated with IceCube astrophysical neutrinos using the FACT, H.E.S.S., MAGIC and VERITAS telescopes,
PoS(ICRC2017) 618

[56] R. Lauer et al., (HAWC, FACT), Joint analysis of TeV blazar light curves with FACT and HAWC,
PoS(ICRC2017) 625

[55] T. Kintscher et al., (IceCube, FACT, MAGIC), IceCube Search for Neutrinos from 1ES 1959+650: Completing the Picture,
PoS(ICRC2017) 969

In: proceedings of the 35th ICRC, Busan, 2017 http://pos.sissa.it/cgi-bin/reader/conf.cgi?confid=301

2016:

[54] D. Dorner et al. First Study of Combined Blazar Light Curves with FACT and HAWC,
Proceedings of the Gamma 2016 Conference, Heidelberg

[53] G. Cologna et al. The Exceptional Flare of Mrk 501 in 2014: Combined Observations with H.E.S.S. and FACT,
Proceedings of the Gamma 2016 Conference, Heidelberg

[52] A. Biland et al., FACT: status and experience from four years of operation of the first G-APD Cherenkov Telescope,
Proc. SPIE 9906, Ground-based and Airborne Telescopes VI, 99061A, (July 27, 2016); doi:10.1117/12.2232600

[51] S. Mueller et al., Bokeh mirror alignment for Cherenkov telescopes,
Proc. SPIE 9908, Ground-based and Airborne Instrumentation for Astronomy VI, 99084O (August 10, 2016); doi:10.1117/12.2232561

[50] M.L. Ahnen et al., Bokeh mirror alignment for Cherenkov telescopes,
Astropart. Phys. 82 (2016) 1-9

[49] M.L. Ahnen et al., Normalized and asynchronous mirror alignment for Cherenkov telescopes,
Astropart. Phys. 82 (2016) 56-65

ATEL
[A6] #9239: FACT: FACT measures new maximum flux from the HBL 1ES 1959+650 at TeV energies
[A5] #9203: FACT, MAGIC: FACT and MAGIC measure an increased gamma-ray flux from the HBL 1ES 1959+650
[A4] #9148: FACT, MAGIC, VERITAS, Fermi-LAT, Swift-XRT: Further increase of gamma-ray emission from the HBL 1ES 1959+650
[A3] #9139: FACT: FACT measures increased gamma-ray flux from the high-energy peaked BL Lac object 1ES 1959+650 since five nights
[A2] #9137: FACT, HAWC, Swift-XRT: Enhanced and increasing activity in gamma rays and X-rays from the HBL Mrk421
[A1] #9010: Fermi-LAT, FACT, MAGIC, VERITAS: Fermi-LAT, FACT, MAGIC and VERITAS detection of increasing gamma-ray activity from the high-energy peaked BL Lac object 1ES 1959+650

2015:

[48] M.L. Ahnen et al., Data compression for the First G-APD Cherenkov Telescope,
Astronomy and Computing 12 (2015) 191-199

[47] D. Dorner et al., FACT - Monitoring Blazars at Very High Energies,
2014 Fermi Symposium proceedings, eConf C14102.1

34th ICRC (the Haag, 2015)

[46] A. Biland et al., FACT - Status and Experience from Three Years Operation of the First SiPM Camera,
PoS(ICRC2015) 1032

[45] D. Dorner at al. FACT - TeV Flare Alerts Triggering Multi-Wavelength Observations,
PoS(ICRC2015) 704

[44] D. Neise et al., FACT - Performance of the First SiPM camera,
PoS(ICRC2015) 706

[43] F. Temme et al., FACT - First Energy Spectrum from a SiPM Cherenkov Telescope,
PoS(ICRC2015) 707

[42] M. Noethe et al., FACT - Calibration of Imaging Atmospheric Cerenkov Telescopes with Muon Rings,
PoS(ICRC2015) 733

[41] J. Buss et al., FACT - Influence of SiPM Crosstalk on the Performance of an Operating Cherenkov Telescope,
PoS(ICRC2015) 863

[40] K. Bruegge et al., FACT-Tools - Streamed Real-time Data Analysis,
PoS(ICRC2015) 865

[39] S. Mueller et al., FACT - Novel mirror alignment using Bokeh and enhancement of the VERITAS SCCAN alignment method,
PoS(ICRC2015) 976

[38] G. Hughes et al., Study of the extreme flaring activity of Mrk501 during multi-wavelength observations in 2012,
PoS(ICRC2015) 806

In: proceedings of the 34th ICRC, the Haag, 2015 http://pos.sissa.it/cgi-bin/reader/conf.cgi?confid=236

2014:

[37] A. Biland et al., Calibration and performance of the photon sensor response of FACT --- the first G-APD Cherenkov telescope,
JINST 9 P10012 (2014)

[36] D. Dorner et al., FACT - STATUS AND FIRST RESULTS,
Acta Polytechnica, 54 3 (2014)

[35] K. Meier et al., FACT - LONGTERM MONITORING OF BRIGHT TeV BLAZARS,
Acta Polytechnica, 54 3 (2014)

[34] T. Bretz et al., FACT -- Operation of the First G-APD Cherenkov Telescope,
19th IEEE Real-Time Conference, Nara, Japan (2014)

2013:

[33] H. Anderhub et al., Design and operation of FACT - the first G-APD Cherenkov telescope,
JINST 8 P06008 (2013)

[32] T. Bretz et al., FACT -- The G-APD revolution in Cherenkov astronomy,
Proceedings of the Nuclear Science Symposium and Medical Imaging Conference (IEEE-NSS/MIC), 2013

33rd ICRC (Rio de Janeiro, 2013)

[31] D. Dorner et al., FACT - Long-term Monitoring of Bright TeV-Blazars,
http://arxiv.org/pdf/1311.0478

[30] T. Bretz et al., FACT - Threshold prediction for higher duty cycle and improved scheduling,
http://arxiv.org/pdf/1308.1516

[29] T. Bretz et al., FACT - How stable are the silicon photon detectors?,
http://arxiv.org/pdf/1308.1515

[28] T. Bretz et al., FACT - The First G-APD Cherenkov Telescope: Status and Results,
http://arxiv.org/pdf/1308.1512

[27] A. Biland et al., FACT - Towards Robotic Operation of an Imaging Air Cherenkov Telescope,
http://arxiv.org/pdf/1307.7892

[26] M.L. Knoetig et al., FACT - Long-term stability and observations during strong Moon light,
http://arxiv.org/pdf/1307.6116

[25] D. Hildebrand et al., FACT - Measuring Atmospheric Conditions with Imaging Air Cherenkov Telescopes,
http://www.cbpf.br/~icrc2013/papers/icrc2013-0709.pdf

In: proceedings of the 33rd ICRC, Rio de Janeiro, 2013, http://www.cbpf.br/~icrc2013/proc_icrc2013.html

2012:

[24] T. Bretz et al., FACT - The first G-APD Cherenkov telescope (first results),
5th International Meeting on High Energy Gamma-Ray Astronomy. AIP Conference Proceedings, Volume 1505,

[23] H. Anderhub et al., Electronics for the camera of the First G-APD Cherenkov Telescope (FACT) for ground based gamma-ray astronomy,
JINST 7 C01073 (2012)

[22] T. Bretz et al., A status report: FACT - a fact!,
Proceedings of the 13th ICATPP Conference http://dx.doi.org/10.1142/9789814405072_0005

2011:

[21] H. Anderhub et al., FACT---The first Cherenkov telescope using a G-APD camera for TeV gamma-ray astronomy,
NIM A Volume 639, Issue 1, 21 May 2011, Pages 58-61

[20] H. Anderhub et al., Results of the prototype camera for FACT,
NIM A Volume 639, Issue 1, 21 May 2011, Pages 55-57

[19] H. Anderhub et al., A G-APD based Camera for Imaging Atmospheric Cherenkov Telescopes,
NIM A Volume 628, Issue 1, 1 February 2011, Pages 107-110

32nd ICRC (Bejing, 2011)

[18] B. Huber et al., Solid light concentrators for small-sized photosensors used in Cherenkov telescopes,
http://dx.doi.org/10.7529/ICRC2011/V09/0136

[17] P. Vogler et al., Trigger and Data Acquisition electronics for the Geiger-mode avalanche photodiode Cherenkov Telescope Camera of FACT,
http://dx.doi.org/10.7529/ICRC2011/V09/0389

[16] T. Kraehenbuehl et al., Calibrating the camera for the First G-APD Cherenkov Telescope (FACT),
http://dx.doi.org/10.7529/ICRC2011/V09/0529

[15] A. Biland et al., First Results from the First G-APD Cherenkov Telescope,
http://dx.doi.org/10.7529/ICRC2011/V09/1125

[14] T. Bretz et al., Status of the First G-APD Cherenkov Telescope (FACT),
http://dx.doi.org/10.7529/ICRC2011/V09/1132

In: proceedings of the 32nd ICRC, Bejing, 2011 http://www.ihep.ac.cn/english/conference/icrc2011/paper/

2010:

[13] H. Anderhub et al., FACT -- the First Cherenkov Telescope using a G-APD Camera for TeV Gamma-ray Astronomy,
HEAD 2010, Big Island, Hawaii, March 1-4, 2010

2009:

[12] I. Braun et al., First Avalanche-photodiode camera test (FACT): A novel camera using G-APDs for the observation of very high-energy gamma-rays with Cherenkov telescopes,
NIM A Volume 610, Issue 1, p. 400-403

[11] H. Anderhub et al., A novel camera type for very high energy gamma-ray astronomy based on Geiger-mode avalanche photodiodes,
JINST 4 P10010 (2009)

[10] M. Backes et al., Long-Term Monitoring of Bright Blazars with a Dedicated Cherenkov Telescope,
Int. Journal of Modern Phys. D, Volume 18, Issue 10, pp. 1645-1649 (2009)

[ 9] T. Kraehenbuehl et al., Geiger-mode avalanche photodiodes as photodetectors in Cherenkov astronomy,
PoS PD09 (2010) 024

31st ICRC (Lodz, 2009)

[ 8] Q. Weitzel et al., A Novel Camera Type for Very High Energy Gamma-Astronomy>

[ 7] I. Braun et al., Solid Light Concentrators for Cherenkov Astronomy

[ 6] T. Bretz et al., Status of the DWARF project for long-term monitoring of bright blazars

[ 5] T. Kraehenbuehl et al., Geiger-mode Avalanche Photodiodes as Photodetectors in Cherenkov Astronomy

[ 4] M. Backes et al., Long-term monitoring of blazars - the DWARF network

In: proceedings of the 31st ICRC, Lodz, 2009 http://icrc2009.uni.lodz.pl/proc/html/

2008:

[ 3] T. Bretz et al., Long-term monitoring of bright blazars with a dedicated Cherenkov telescope,
Proceedings of the 4th International Meeting on High Energy Gamma-Ray Astronomy. AIP Conference Proceedings, Volume 1085, pp. 850-853 (2008)

[ 2] T. Bretz et al., Long term VHE gamma ray monitoring of bright blazars with a dedicated Cherenkov telescope,
Proceedings of the Workshop on Blazar Variability across the Electromagnetic Spectrum. April 22-25, 2008 Palaiseau, France.

2007:

[ 1] A. Biland et al., First Detection of Cherenkov light from cosmic-particle-induced air showers by Geiger-mode avalanche potodiodes",
NIM A, Volume 581, Issues 1-2, 21 October 2007, Pages 143-146

30st ICRC (Merida, 2007)

[ 0] T. Bretz et al., Long-term VHE gamma-ray monitoring of bright blazars with a dedicated Cherenkov telescope,
https://indico.nucleares.unam.mx/event/4/session/40/contribution/974

In: proceedings of the 30st ICRC, Merida, 2007

[xxx] FACT Collaboration Publications and Proceedings
[Axx] FACT Collaboration Astronomical Telegram
[Txx] related technical publications, reduced authorlist