The magnesium paradigm in IRC+10216: Discovery of MgC$_4$H$^+$, MgC$_3$N$^+$, MgC$_6$H$^+$, and MgC$_5$N$^+$

J. Cernicharo; C. Cabezas; J. R. Pardo; M. Agúndez; O. Roncero; B. Tercero; N. marcelino; M. Guélin; Y. Endo; P. deVicente

doi:10.1051/0004-6361/202346467

paper

The magnesium paradigm in IRC+10216: Discovery of MgC $_{4}$ H $^{+}$ , MgC $_{3}$ N $^{+}$ , MgC $_{6}$ H $^{+}$ , and MgC $_{5}$ N $^{+}$

arXiv:2304.05117 · doi:10.1051/0004-6361/202346467

Abstract

We found four series of harmonically related lines in IRC\,+10216 with the Yebes\,40m and IRAM\,30m telescopes. The first series corresponds to a molecule with a rotational constant, $B$ , of 1448.5994 $\pm$ 0.0013 MHz and a distortion constant, $D$ , of 63.45 $\pm$ 1.15 Hz and covers upper quantum numbers from $J_{u}$ =11 up to 33 (B1449). The second series is fitted with $B$ =1446.9380 $\pm$ 0.0098 MHz and $D$ =91 $\pm$ 23 Hz and covers upper quantum numbers from $J_{u}$ =11 up to 17 (B1447). The third series is fitted with $B$ =598.7495 $\pm$ 0.0011 MHz and D=6.13 $\pm$ 0.43 Hz and covers quantum numbers from $J_{u}$ =26 up to 41 (B599). Finally, the frequencies of the last series of lines can be reproduced with $B$ =594.3176 $\pm$ 0.0026 MHz and $D$ =4.92 $\pm$ 1.16 Hz (B594). The large values of $D$ point toward four metal-bearing carriers. After exploring all plausible candidates containing Na, Al, Mg, and other metals, our ab initio calculations indicate that the cations MgC $_{4}$ H $^{+}$ , MgC $_{3}$ N $^{+}$ , MgC $_{6}$ H $^{+}$ , and MgC $_{5}$ N $^{+}$ must be the carriers of B1449, B1447, B599, and B594, respectively. These cations could be formed by the radiative association of Mg $^{+}$ with C $_{4}$ H, C $_{3}$ N, C $_{6}$ H, and C $_{5}$ N, respectively. We calculated the radiative association rate coefficient of Mg $^{+}$ with C $_{4}$ H, C $_{3}$ N, C $_{6}$ H, and C $_{5}$ N and incorporated them in our chemical model. The results confirm that the Mg-bearing cations can be formed through these radiative association reactions in the outer layers of IRC\,+10216. This is the first time that cationic metal-bearing species have been found in space. These results provide a new paradigm on the reactivity of ionized metals with abundant radicals and open the door for further characterization of similar species in metal-rich astrophysical environments.

The magnesium paradigm in IRC+10216: Discovery of MgC $_{4}$ H $^{+}$ , MgC $_{3}$ N $^{+}$ , MgC $_{6}$ H $^{+}$ , and MgC $_{5}$ N $^{+}$

Abstract

References in corpus (16)

Cited by in corpus (9)

The magnesium paradigm in IRC+10216: Discovery of MgC4​H+, MgC3​N+, MgC6​H+, and MgC5​N+

Abstract

References in corpus (16)

Cited by in corpus (9)

The magnesium paradigm in IRC+10216: Discovery of MgC $_{4}$ H $^{+}$ , MgC $_{3}$ N $^{+}$ , MgC $_{6}$ H $^{+}$ , and MgC $_{5}$ N $^{+}$